Power Production Update

At the end of November we had a surprising 400-some KWh in credits on our meter. After 28 days of snow and clouds, I suspected we would have burned that up by far. When I checked the meter 12/28, I saw we had finally bought 122 net KWh from the grid. I never thought we could get this far into winter before dipping into the grid. The gridtie system has performed beyond expectations here in the West Virginia hills and hollers. Can't wait to see when we get back into credit territory.

Return of the Sun, Eclipse of the Moon.

Ever since near the end of November to present, our weather has been unusually cold, snowy, and cloudy. It's the kind of weather you would more expect in January. Needless to say, it really knocked a hole in our PV production. Our predicted harvest was for 216 KWh, the lowest month of the year. So far, we have only captured 96 KWh and it is the 20th already. This is where the climate averages play in. Even though this month is bad, last month was well above average. That's why you can't get freaked out over unusual circumstances with solar, it all works out in the long run.
One thing to celebrate is the Winter Solstice on the 21st. It is symbolic mostly, however it does mean that the sun will be rising ever higher and the days become longer. That's about all we can reinforce ourselves with as we enter January and the bottom of winter. By March, we are predicted to produce 435 KWh, twice as much as December. I think that's plenty to look forward to.
As an interesting note, around 3am tomorrow morning, there will be a total lunar eclipse. It will be the first one to fall on the Solstice in over 400 years and we can all witness it as long as it's not... CLOUDY.

Shadow Study

One thing you can do on snowy days is to explore the capabilities of your computer. I regularly use Google Earth to study PV site for potential customers. This time I decided to model our proposed shop PV array using Google SketchUp (free, google it) The sketchup program can use Google Earth data for shadows and geophysical features. There's a control where you can set anytime of the day, any day of the year, to see how the sun's shadows affect your array. Even nearby mountains will cast their shadows accurately.
I wanted to confirm my row spacing for maximum module density without interference. It takes awhile to get a handle on modeling in sketchup, but its time well spent. I will use this tool to prove the design is good for a grant we are pursuing and see how roof angles and protrusions may influence some future complex new install.

Winding Down

After finishing the job described on the previous post, I thought there would be a quiet period while winter ramped up. To our surprise we started a job on a new home site by setting poles for a top of pole PV installation. We'll try to get all the conduit laid while the builder is there with excavation equipment. At some point he'll have to shut down during any severe weather. We'll pick it up again when the weather returns to bearable.
It's been unusually cold and cloudy for the past week and we're using our last couple hundred KWh's in credit on our meter. To our further surprise it looks promising for another PV job where the owner wants to spend the money this year for tax purposes. We'll work on that one as the weather opportunities arise.
In the photos above you can see the pole fabrication in progress. I want to thank Lola Alderman for helping and doing a fine job on finishing. By the way, that's my new forklift I got to unload trucks delivering pallets of PV modules. In fact, its only new to me, it has some hours on it and I had to rebuild some linkages and fit chains to the tires. We couldn't afford a forklift that didn't need fiddling, so I'm happy to do it. It runs well and we might even paint it.
The pic of the PV array is the one at our house after days of snow showers. The deep blue sky is a wonderful sight. I didn't brush off the snow so I could see how it melts and slips off with a little sunshine. It took 4 hours to clear itself that sunny morning.

Final Day On the Roof

Due to the fact a recent customer decided to get a new roof before we install, and waiting on back-ordered parts, we are finally here on November 22nd for the panel installation. Ominous weather forecasts and Thanksgiving pushed us to work on the weekend and Monday to get off the roof part of the installation. As you can see the weather was perfect that day. Now, all thats left is the homerun wiring and disconnect that aren't so weather critical.
This is a grid tie net metering system with 24 modules rated at 220 watts for 5280 watts STC total. The inverters are Enphase D380's that connect to two modules each. This made wiring simple and less expensive than traditional systems. After inspection, our power company must follow through with their end of the deal. They have been rather slow about getting the new meters installed lately, and we hope sometime in December our customer will be enjoying the benefits of solar power. That will be the weakest solar month of the year for production but they can look forwards to really gaining output as the season progresses. This system should harvest 6 MWh/year given his exposure and some trees in the way in the morning and evenings. His SRECs should yield $1800 a year not including the "free" electricity.
Speaking of weather, I looked at our meter today and was surprised to see we had 460 KWh in credits. I can only attribute that the ongoing drought has produced more than usual sunny days and we have not used as much electricity. Next week is December and I suspect we will use those credits up if the cloudy days come. None the less, I am delighted we went this far without using net grid power.

Getting Better

The image is from the Open PV Project of the National Renewable Energy Laboratory. It shows the national average cost of an installed PV system at $7.15/ watt. Our last few installs worked out to be about $5.50 to 6.00/ watt. These were projects that were pretty straight forward roof mount, grid tie systems. Special mounting options or offgrid installations are more expensive.
Our selection of the latest technology and reduced panel prices have contributed to making solar more affordable. Being able to take advantage of the tax credits reduces the cost even more.
Let's hope America continues to promote all types of renewable energy for far into the future. We need it.
Alterra Renewable Energy

The Evolution of Lighting

When I was a kid watching Voyage to the Bottom of the Sea on TV, there was a scene that facinated me so much, it is clear in my head to this day. In the 1965 episode called "The Invaders" Robert Duvall played a being from a 20 million year old race that disappeared from Earth. The scene shows Commander Lee Crane getting acquainted with this advanced entity. The being reached up to a light fixture in the submarine and said:"your lights emit unnecessary heat". Followed by: "you have not learned how to conduct electricity without...wires?"
Somehow, those lines made an impression upon me and how to gauge what the future would be like.
Today, with the availability of compact florescent bulbs with good efficiency and being relatively inexpensive, that was the first improvement over standard incandescents. I knew we were finally on track to becoming an advanced race. I'd been waiting 40 years after all.
CFLs are a step in the right direction, but they are still relatively inefficient, thus giving off a fair amount of heat. I was walking through Lowes the other day and stopped by the LED shelf to see how that technology/cost is coming. I saw that a 40 watt equivalent, 8 watt actual, was available at around 19 bucks. Much better than even a few months ago. I bought one.
When I got home I was anxious to screw it in a lamp socket and perhaps have light without heat. After waiting a while, it got warmer and warmer, but still cooler running than a CFL and vastly superior to a scorching incandescent.
We're not yet in the future as I have been waiting for, but there are substantial improvements in conservation ready to use. LEDs hold the best promise once efficiency is improved. Right now, a LED lamp boasts 50,000 hour lifetime. That would be like burning 5 hours a day for 27 years. Think of how many CFLs (8000 hours) and standard bulbs (1500 hours) would not have to be made and replaced. LEDs do not contain mercury like CFLs and the emissions from a coal fired power plant. More conservation, less emissions, less mercury.
Let's compare the costs of installing a solar electric system to the different types of bulbs discussed. The basis will be 5 hours a day for the bulbs and 5 peak sun hours/day for the PV. The current cost per installed watt of a PV system is running around $5.50/watt.

40 watt incandescent-retail price: $1.50- daily consumption: 200 watt/hrs.
Cost of PV system to run it: 40 x $5.50=$220.00

40 watt equivalent, 11w actual CFL- retail $4.00- daily consumption: 55 watt/hrs.
Cost of a PV system to run it: 11 x $5.50=$60.00

40 watt equivalent, 8 watt actual LED-retail $19.00- daily consumption: 40 watt/hrs
Cost of a PV system to run it: 8 x $5.50=$40.00

Although you really couldn't or even want to install such a small (40 watt) grid tie array, this is just looking at a slice of the consumption/production ratio. Conventional wisdom in PV land is that for every dollar spent on conservation, you would save about 4 or 5 bucks trying to make the power yourself. If you have huge power bills, a substantial PV installation would be a disappointment. If you work down your usage, the PV investment will represent a larger percentage of your consumption and the experience will be satisfying. By the way, I just checked our power meter on Oct 25th and we had 490 kWh in credits. I was totally amazed we were "still in the black" coming up on November. We have not used any net grid power (read: no power bill) since we went online June 8th 2010. This is only possible because we reduced our use over the previous two years. It not hard, it just takes discipline and smart choices.

PV and the State of the Economy

We have two nice PV jobs to get done before the snow flies. Timing is everything in the logistics of pulling the various parts together on the sites. In the past, its been a matter of placing an order with a couple of suppliers and the parts would show up in a reasonable amount of time. As this year marched on, I noticed the cupboard shelves for PV parts getting a bit thin.
The past two weeks I spent an inordinate amount of time emailing and finding alternate sources for the required parts. Some of the parts have a particular spec that affects another part's compatibility. So, it cascades though your parts list, if you change one spec in order to get the job done. All this adds stress to my job and it seems the suppliers have no remorse for the inconvenience.
My theory is that industry and corporations are hoarding cash to hedge any uncertainty in the future economy. They reduce their inventories, cut costs, and production so they don't spend as much money. This means they're not much into hiring either. Those reduced supplies trickle down to the distributors and me, the installer. The banks are the same way, reluctant to lend money while they are sitting on huge cash reserves.
No amount of stimulus will undo this mindset. If our economy is to proceed, big business must boost productivity and hire more personnel. Until that happens, our economy will just flounder along and the consumer will have no confidence to invest in solar or efficiency improvements into their lifestyles. Someone must make the move.
On the benefit side of our lousy economy, PV module prices have dropped dramatically over the past year or so. Last summer module prices were about $3.50 per watt. This year we are selling at $2.50 per watt. Part of this was a glut in supply caused by everyone jumping into the PV manufacturing business, especially the Chinese. On the other hand, the consumer pulled back on actual spending, even though interest in renewable energy is spreading through our country.

Solar back on the White House

Well it's finally happening, Obama has decided to mount solar electric and thermal on the roof of the White House. Actually there are small installations on the grounds, but they received little fanfare from the press.
http://news.yahoo.com/s/ap/20101005/ap_on_bi_ge/us_white_house_solar_power
The picture at the top of this page was composed earlier this year as I had the dream of being the installer. I tried many emails and maybe one got through to him. There were several groups putting the pressure on to make it so.
So far, I didn't get any calls to do a site assessment for the White House, but I'm faintly hopeful.

Sooo Wrong

Tenley and I were driving to a site assessment when we went by a school zone. After getting past the first sign and towards the end of the zone, I realized that the PV modules where pointing towards each other. We were on a north-south highway, so one of the modules was bass ackwards.
If you look to the left in the distance you'll see the correct one facing roughly southwest. If you look to the right side you will see the pv module looking northeast. Only a summer sunrise will barely light it's face and in the winter, not a chance. This module will only gather a small fraction of the solar energy from back scatter in the atmosphere. I don't know if this is a new installation and the shortcoming not yet realized or it has enough reserve to keep functioning during the school year.
If you study the sign on the right you'll see that the pole is not tall enough to turn the module around. There was also some attempt to force-twist the frame further east. Who ever installed the signs went ahead with the short poles and hoped for the best, it was time to go home for dinner. It looks to me like the frame could be swiveled much further east to acquire more gain. The correct answer is to put in a pole about 3 or 4 feet taller and swing it around due south without blocking the signal or sign.
Best practice in solar installations is to be within 20 degrees either side of south. In a pinch up to 30 degrees off is acceptable with only about 4% loss of energy harvest depending on module tilt.
Solar installations are just starting to become popular so there are not many experts out there. But in a situation like this it ought to be a no-brainer....

PV Announcement

We have decided to pursue an ambitious solar project at Alterra's shop building. The project involves 20 kilowatts of installed generating power to the roof of the shop. This installation will be one of the largest to date in West Virginia. It will be able to produce enough surplus power (25 Megawatt-hours/year) that we can get rid of our propane heat and have plenty left over for AC, daily operations, and future expansion. The generated power will produce a cash flow to payoff a short term loan as long as we also get two different grants. After its paid, the system will produce substantial income for years to come.
As the pieces come together, we will be reporting on the progress. We have already started roof preparation and reinforcement for the weight. We also have a work request number with Allegheny power who we will net meter. There's a lot of design and paperwork to go but we think this plan is worth the effort. Stay tuned as this plan comes together. It is especially valuable for small businesses.

The Tale of a PV Installation, Part 2

Where was I......Oh yeah, I was at the beach while Hurricane Earl clipped by. No internet, no need. When we got home, it took 4 or 5 days to become officially caught up with unfinished business. Now for the rest of the story.
We left our heroes in the blazing sun assembling the PV modules. Our progress was pretty smooth until around noontime. By then it was 90 and humid. Plenty of water was dispensed with retreats to the shade trees. Originally, I decided upon two morning stints to get this part done. We were finished with 3 out of 4 arrays and the boys wanted to push on. I reluctantly agreed.
It wasn't long before I heard fasteners and tools begin to tumble off the roof. I knew the heat was bearing on the roof guys. I had to demand they take a break with only two more modules to go. Once refreshed, we pushed the last bit of energy to complete all 20 modules. Joe had to stay up to make final connections at the roof junction box. It seemed like an eternity but he was quite the athlete pushing through. When all were on the ground we all felt pretty good about today's accomplishments. Time to gather the tools.
I walked back into the yard to get a wide view of the installation. One of the owners asked me why the last column of modules looked askew. I looked from different angles and by golly, they were off by under an inch. I sort of groaned to my self knowing we might have to realign that day in the heat. So we tried offsetting modules to close the gap. It was soon apparent 4 of 5 must be removed and the starting module aligned correctly. I told the customer that I need to think about it a bit. We had gained nothing by pushing through the last column in the heat. Fatigue dulled our eyes and brains. We'll have to come back anyway. Lesson learned.
But hey, we could give the system a test! We started the Envoy (array interface) and the microinverters. I takes time at first while the microinverters report to the Envoy and it starts logging in the units. We waited a half hour but only came up with 10 units. Something wrong. We checked the branch box and reset the breakers. Nothing. Then I asked Joe to put a meter on the output side of the breakers. One of the two was dead. Joe and I have never bought a new breaker and have it bad, but there it was. Joe offered to run to town for a replacement. He was back in no time and installed the new breaker. We flipped them on and and went back to the Envoy. In a few minutes we had 15 or so and a few minutes more, all 20! Great, we were pumping nearly 2800 watts, everyone felt happy and relieved. So we shut the system down and told Glenn its in the power company's court and that we would return in a few days to align the modules. Meanwhile, I contacted the electrical inspector Ray Still of Alderson, WV. He contacted Glenn, made arrangements, and he was on site that evening. What good service. The system passed all codes and requirements.
Early the next week, we all showed up to tweak the modules. After an hour or so, we had them true and we were done with the job. Glenn and I discussed the power company's inaction and promised I would call all my contacts to find out the status. I found out that we have a work order number, but no $30 application payment or inspection report. I knew both items were taken care of but they didn't know it. Glenn was starting to get a bit annoyed at the power company. He would say;"I have these panels on the roof and all this sunshine is going to waste!" I assured him that the sun has been burning for 6 billion years and we have quite a few billion to go. I know his feelings exactly. It happened to me when I was waiting for our system to go online.
Glenn and I finally figured out we were getting the runaround. With both of us calling and emailing everyone finally someone from the local office showed up to check the meter base. All I could do is assure Glenn it will all happen, eventually.
And eventually it did, while I was at the beach. Glenn now turned compulsive, reading the Envoy and checking the new bidirectional meter readings. Once again, I've been there. It is one of the most rewarding experiences of having a PV system. It feels all warm and fuzzy.
I hope that as PV systems are installed in the region, the power company will be more friendly, accepting, and knowledgeable about this upcoming change in the way they have been running the grid.
I am happy, Glenn and Susan are happy, and anyone else involved with this new wave of independent power. A better word may be distributed power as opposed to centralized. Power to the people!

2nd Report, Net Metering

I posted a progress report back on August 20th showing our 183 kwh credits with the power company. Yesterday, Sept 10th, I took the above pic showing us with 333 kwh in the bank only 21 days later. What helped us to pack it on was a change in the weather pattern to dry clear days. We have been producing 20 to 22 kwh on most days for the past two weeks. Another important factor was that we were away from home for 10 days thus reducing our demand. It's these kinds of circumstances that can gang up to produce twice what you expect. Then there are the times when things gang up and disappoint.
When living with solar, you'll have your ups and downs on the short term. We calculate future production with the solar aperture and long term climatological data for the site.(plus other things) For sure, the slate gray skies of winter will be a bummer, but you'll be prepared with hopes of near term improvements.
Back on the August 20th post, I mentioned we were running behind due to a cloudy pattern that month. Our prediction was for 497kwh and the partial month's data suggested 446kwh. What we actually closed with was 476kwh. We'll take that.
If September's weather stays the same we could see near 600kwh for the month. Of course, by then we would be in drought conditions, not good.

The Tale of a PV Installation: Part 1

Back in July,I received a phone call from a couple interested in PV net metering. They were at a local HVAC business called Total Tech in Frankford, WV. As it turned out, they were finishing business concerning a geothermal heatpump system just installed at their new house. Wayne at Total Tech referred us as solar installers. I said sure, come on up, its only 9 miles up the road.
When they arrived we introduced ourselves and I began to query about their needs, desires and home site. This info gives me a better handle on what to present as options for system design.
The couple's names are Glenn Freeman and Susan Mitchell and they are in the process of moving to their new home on Muddy Creek Mountain in Greenbrier County, WV. They are retirees from New Jersey and was just a matter of a couple weeks before they say goodbye to Jersey and hello to West Virginia. It must have been a brave decision to make such a commitment. I think they will adjust well to the local mixed culture and what the mountains have to offer.
Anyhow, we sat in front of my computer and scanned Google Earth for their home site. The aerial photo was dated but we did find the clearing in the woods where the house sits now. I was a bit concerned about the ring of trees shading the array, so I suggested an on-site assessment.
Once I arrived, I was quite impressed with the style, quality, but appropriate size of the dwelling. Previously they had a solar consultant recommend siting, orientation, and roof pitch for the architect and builder. With the geothermal heatpump delivering 4kw of heat for every kw put in, they reduced their demand so that the PV array would provide a substantial contribution percentage-wise. We came to the conclusion that a 3600 watt array was a good starting point while having enough capacity built in so they could easily add 1800 or another 3600 watts over time. After taking some measurements for solar aperture, looking at wire run options, and roofing material, I told them I would be a couple days before presenting the results.
Back at the office, I plugged in the data into a program I assembled to provide performance, cost, tax incentives, and potential SREC value. SRECs stand for Solar Renewable Energy Credits and can be auctioned off to utilities in surrounding states. These utilities will pay up to $0.33 per kilowatt hour you produce instead of installing RE mandated content in their own grid.
Once satisfied with the general design and results, I emailed the docs to them. They soon called and said they were interested. Once I received an engineering deposit, I proceeded to create a detailed hard quote, wiring diagram, and agreement. I went to their place and discussed the details and answered questions. Upon signing the agreement, I requested a deposit and gave them the document to apply for net metering with Allegheny Power.
As soon as I got home the deal went into high gear. I researched availability of the parts through my various distributors to get the best prices and shipping costs. Once decided, I pulled the trigger and made the orders. It didn't take long for the smaller parts to arrive via UPS. The modules had to come by truck, so that took longer.
Once I had the mounting system in hand, which is a clamping system for standing seam roofs, I began to doubt whether they would work. So I drove back to the site and tried one on the seam. It didn't fit...crap. Instead of parallel, vertical seams, these had a truncated triangle profile. No amount of crushing or modification would make for a strong connection. Plan B.
I immediately ordered some UniRac SolarMount rails and clamps. These had to come by truck, so I put the hot rush on it. Meanwhile, I got a RMA to return the other mount system (at a 15% restock charge). The rails got here in a few days, no time lost. This was all my fault for not inspecting the seams closer. I figured standing seam was standing seam. These are the kind of gotchas that happen when you fail to focus on every detail even if you think you know what's going on.
By the time I had the rails and microinverters, it was blazing record hot for weeks around here. Add to that the brown tin roof and the installation windows were mornings only.
In a moment of inspiration, I thought why not populate the rails with the microinverters and roof anchors in my shop? That would prevent a lot of roof time precisely positioning the components on 130 degree tin. It took half a day on the workbench to mount the parts.
So we scheduled a rail install day and got them all up in a few hours. And they where pre-wired and pre-grounded boot!
In the meantime Joe, our licensed electrician, began to run wires in the house and mounted a breaker/disconnect box on an outside wall. He took the wires though the attic crawl space ready to punch through the roof once the modules are mounted.
My wife, Tenley and I delivered the modules on a Saturday since our truck had to go to a garage for a week. Susan and Glenn helped us lift them over the porch rail and made a neat stack. We strapped them together and covered them in case some rogue wind came through before the install.
I kept watching the NOAA weather forecasts online looking for a day with some heat relief. No, just relentless heat as far as you could see. I decided to break the module install into two mornings. Once we got there, there was dew on the roof (can't win for losin') After progressively toweling down the tin, we mounted the two grab ropes to assist our traction.
The first few modules established the flow required to be efficient. Like; where someone was at a given moment, what small parts in the belt bag, tools handy, knowing where the grab rope was, and getting the position of the first module straight and square. Our boots-on-the-roof guys were Joe the electrician, and Michael our electronics tech and fabricator. I was on the ground trying to think ahead about any glitches and providing parts, modules, and tools.
This is the end of part one, part two will be posted before too long.

Proof of concept, Labor of love

When we first installed our evacuated tube solar hot water system, it got me thinking about the heat we had to dump because we had to keep the water tank below 170 degrees F. The other piece of intriguing information is that these tubes could attain a temperature of 375+ degrees if the glycol solution was not flowing.
As we were enjoying the abundance of solar domestic hot water available, my mind kept thinking about other potentials for this high temperature fluid. At first, I thought about steam production to run a steam engine and in turn a generator. I have done extensive prototyping of variations of steam schemes that would make a carefree power source. I never even got close. Steam power requires constant fiddling and water freezes at 32 F., not a practical source of continuous power.
A few months went by and I remembered the Stirling hot air engine.(invented in 1816) No water, no freezing, little maintenance. Not only that, but efficiencies well above steam engines. (up to 40%) My search commenced for a model Stirling motor at modest cost.
Being a machinist and needing some mental diversion, I found a kit that requires machining to assemble from Grizzly. http://grizzly.com/products/searchresults.aspx?q=stirling&new=1
The vertical kit cost 77 bucks, the premachined kit was $164. I opted for the more challenging raw kit knowing I had to convert the metric drawings and some of the material stock to decimal inches. After 3 weeks of part time machining, I got it to a testing level. I put an alcohol burner under the hot end and waited. A little nudge on the flywheel and she started spinning. WOW!
So, I went through a procedure of timing and lubricating until I achieved a speed of 1770 RPM. Wow again. I looked at the size of the flame to the output and thought, this ain't bad.
Once I had a functional engine, I thought about how to power this thing from the sun. Previously, I thought about a huge array of tubes circulating mineral oil at high temperatures to power a more powerful engine. This engine was not in that league, so a more doable solution was needed.
I had Sunda 7 foot evacuated tube with a heatpipe delivery system. The business end can approach 400 degrees when exposed to the sun. So I made an aluminum connector (heat conductor) between the output of the tube to the input of the engine. This will conduct the gathered heat into the engine. (with the aid of a heat conductive paste) I finished up at the end of the day and frantically set up the rig on a board looking at the diminishing sun.
It was already 5:30 pm and the sun was getting weak. I waited for a few minutes and spun the flywheel. It spun eagerly but eventually stopped. Again and again I nudged it hoping for something, anything. After 5 minutes or so, I nudged it and viola, it kept running. As time went by it went faster and faster. Not as fast as the alcohol burner but an impressive seven hundred-some RPM....... Success, Proof of Concept.
The video captures this moment. The video does not capture my elation. It didn't matter that it was no barnstormer, it ran from the heat of the sun. All this work leaves me with a bit of fertilizer for my brain. What I made couldn't power even a laptop, maybe a cell phone. Got that picture in your mind? How convenient.
From here, I'll think about how to upscale this deal. It might have some application, but I'm not betting on it. It will become whatever, this is how innovations evolve.
Before you get carried away with the potential, let me list the ups and downs of this apparatus:
ADVANTAGES:
> Any substantial non-petrol heat source; solar, biomass, wood, etc
> No freezing of water
> No boiler explosions (could be a bummer)
> Relatively few parts, limited wear.
> Quiet
> Clean, external combustion process.
DISADVANTAGES:
> Low power to size ratio (large engine/heavy weight to output ratio)
> Lack of off-the-shelf parts and engines ($+)
> Low torque, unless designed to make it. (at the expense of HP)
> Continuous power/speed only, hard to throttle.
> Needs 4 cylinders to start automatically. ($+, complex)
We're not going to let this stuff stop us, are we????

Progress report, net metering

The above photograph is our meter taken on August 20, 2010. This meter was installed on June 8th of this year. When it was first installed it read "00000". Now it indicates we have 182kwh in credit with Allegheny Power. Considering for the past 40 days we have been into a lot of cloudy and partly cloudy weather, we're doing OK. This number shows the surplus power we generated, not the PV total output.
Through the Enphase Enlighten website which displays and archives our production data, I have prepared a report comparing our actual total PV output to our program we use to predict performance for potential customers who have had a site assessment done by us.
I have a field in the software where I can adjust system efficiency to help make the predictions fit the real world. Normally I use 90% system efficiency for potential customers. This predicts a slightly lower number than what they may see for real. I would rather under promise and over deliver. Our system is calibrated at a brutal 95% efficiency. This is the same efficiency as the Enphase microinverters. One must allow for line losses too, however the Mage PV modules have a higher tolerance for its power rating method which tends to cancel out the other losses.
So, how did we do so far?
From June 8th through to the end of that month, we produced 390kwh. If you adjust that for a full 30 days, you would have 585kwh. We predicted 507kwh, and overshot the prediction by 78kwh. yeah!
July is our only full month so far. We produced 545kwh, we predicted 497kwh. Again overshot by 48kwh. yeah!
So far in August, up to the 19th, we produced 288kwh. If you extrapolate out to 31 days, it would be 446kwh. Our prediction is 497kwh (same as July). Here we undershot the prediction by 51kwh. boo! This was mostly due to persistent cloudy weather patterns. If we have a week of more clear weather, we will easily surpass the prediction.
To date, we only have a small data set to work with. It would take two years of data to confirm everything is true. I feel confident that both the system and the predictions are within tolerance. These two items are quite important to a customer considering making the plunge into PV.

What does power mean? Or, more #@%* math

Many times when I describe how much power a solar array makes, the common question is "just what does that mean, how can I relate to the amount of power produced?"
When talking about power, there are two basic types of power measurement. One is the solar array rating and the other is what it makes over time.
The array rating is usually stated as watts under Standard Test Conditions or STC. These conditions are shining 1000watts of light energy onto one square meter at 25 degrees Celsius. When PV modules are made, the manufacturer "flashes" this amount of energy upon the module being tested. If it falls within tolerance, it passes the test and is labeled as so many watts STC.
The rating therefore is an instantaneous reading of energy output. It really hasn't done any work, since it takes power over time to arrive at an understandable unit of work or power.
Common output instantaneous ratings are described as:
Watt (W, after James Watt, inventor of the steam engine and definition of horsepower)
Kilowatts (KW; 1000 watts)
Megawatts (MW; 1,000,000 watts, 1000KW)
Gigawatts (GW; 1,000,000,000 watts, 1,000,000KW, 1000MW)
and so on.
When describing practical power, you must add the element of time. On average, on a SE West Virginia Summer day, you can expect 5.2 peak sun-hours per day. This unit goes back to the STC thing, 1000 watts per square meter. This is how we quantify solar energy through the seasons with all the clouds, rain, snow, and shorter days thrown in.
So, say you have an array rated at 2000 watts STC on a 5.2 peak sun-hour day. simply multiply 5.2 x 2000 and to get 10,400 watt-hours or 10.4 Kilowatt-hours for the day.
Now, we have something to grab on to, a quantity of useful, practical power.
So, what the hell does a kilowatt-hour mean to ME? Its surprising in this day and age that we are so used to having so much energy at our fingertips. Why, I remember in the old days, (not really) how little power was available to us. Back in days of yore, we had muscle power (human and animal), water and wind power to accomplish our work.
If you had a 1 horsepower electric motor, it would take about 1 kilowatt of electricity to run it. A horsepower is actually 746 watts, but with inefficiencies, it takes about a thousand watts. OK, so a Kilowatt-hour is worth one horsepower-hour, so what? When James Watt experimented with rating horsepower, he used big ol' draft horses, working at peak power over short time frames. When I say peak, the horse was working at levels that were not sustainable. I'm sure you are starting to get a handle on this power.
For you geeks, I'll explain what a horsepower is worth: it is 33,000 ft-lbs per minute. In other words, a horse could lift 33, 000 pounds a distance of one foot in one minute. Conversely, it could also lift one pound, 33,000 feet in one minute or any combination between. That's a bunch of work! In WV, we pay about 9 cents worth of electricity to do the same work. No wonder we have become so detached from the understanding of power and how cheap (artificially) it is.
So, back to the quantity of power from a 2000 watt array. Over the course of a Summer month, you could expect 312 KWh to be produced. You must subtract some power loss from inefficiencies of the inverter, line losses, and the fact that Summer heat reduces output compared to the STC rating. By observation, I determined the Summer efficiency rate of 90-92% for a complete high quality PV system, so my guess you would net 290 KWh.
What are the energy equivalents of that 290 KWh? You could do one the following activities:
>You could run your toaster for 8 days straight and make 4640 slices of toast
>The Budweiser Clydesdale hitch could pull a fully loaded beer wagon, up grade, for 48 hours straight.
>You could vacuum your house for 232 hours straight or 9.6 days, whew!
>Heat 2000 gallons of water from 60 to 120 degrees F.
>Run a large room air conditioner for 6 days, around the clock.
>Drive your car at 40 MPH on a level road for 19 hours and go 773 miles.
>Burn 8 CFL lamps rated at 100 watts of light (23w actual) for 65 days.
> Watch TV (LCD type) around the clock for 80 days, snacks not included.
Now let's look at what the equivalents are when you throw the switch:
>You turn on 4 CFL lamps- a healthy person works at maximum power for a while and the lights go dim as he becomes exhausted.
>Toast a bagel- A large draft horse pulls all it can for about 5 minutes.
>Turn on the room AC-A team of 2 to4 draft horses pull all they can for as long as the AC is on.
>Turn on all electric heat- Your 24hp lawn tractor runs at full bore mowing tall wet weeds.
I hope all this helps you to form some mental images as you go about living and realize how plush we have it, for now.

Bigtime

July 24, 2010. Mountain Messenger newspaper. Lewisburg, WV

West Virginia Enters New Age

Although WV has had net metering provisions they haven't been very good compared to other states. Recently, a new set of rules have been passed by the PSC to put WV's net metering among the best in the country. I am so happy this happened without too much dilution from the powers that be.
Read all about it at http://irecusa.org/2010/07/july-2010-connecting-to-the-grid-newsletter/
Download PDF at bottom of page then go to page 3 to read all about it.
Yeah!

Climate Change Fix

I have no idea how many people read my blog. Other than the occasional comment, there is no counter of visitors to gauge the readership. I hope this blog can be an effective tool to plant some ideas that can help raise the awareness of important issues.
My usual M.O. is to approach softly and supply facts and figures to support an issue. Sometimes it's subtle promotion of concepts, our solar business, or myself. I read an article why people Twitter, YouTube, camgirl, and blog. If there is some sort of audience, it validates your existence. Sometimes the only audience is one's self. Same effect.
The topic covered in this post is global warming. Actually, it needs to be referred to as climate change. We watch the news and are aware of our surroundings. Things are happening to the planet in increasing frequency and intensity. Take last winter for example, I haven't seen a Winter like that since 1976-77 back in Pennsylvania. The cold and snow were caused by El Nino...the WARMING of equatorial waters in the Pacific. Then, in late Winter we went to late Spring weather just like that. Early in July NOAA reported that June was the hottest...ever. July itself is not far behind. I can't remember how many times the temp was over 90, but I cannot recall such a streak in the 32 years I've been here in the high country of WV.
Think hard, how long has it been since you thought some particular season was normal? Isn't every season some sort of a surprise? One can go for years and not realize the accumulation of evidence. I have noticed an increase of poison ivy, and for the first time, found termites. What's next Kudzu? These are signs of a warming West Virginia. They say in a hundred years WV will be a high desert, like in New Mexico.
Headlines abound; 520 Belgians die in heatwave, Argentina braces for severe cold, floods in China and the US midwest. On and on and on. Was the news always like that? Is this Al Gore's doing?
Climate change will effect our clean energy capacity. Right behind the energy crisis is a critical water crisis. As drought deepens in certain areas, the hydroelectric dams are diminishing in output. Not only drought lowers the water levels, but irrigation of the desert takes a huge amount of water. Our current thermoelectric power plants consume and evaporate a tremendous amount of water. What if there is not enough water where and when needed?
CLEAN COAL, Ha! In order to capture the CO2 emissions it will require doubling the water use. How can anyone put up a billboard near Charleston, WV that says COAL...CARBON NEUTRAL. Trees are carbon neutral, not coal. What some groups get away with.
The Earth may have something up her sleeve. If the Greenland ice cap melts off, there is enough fresh water to stop the equatorial conveyor currents from flowing. The result is irreversible, an Ice Age will begin, not over hundreds of years, but within a decade of the currents stopping. That will sure take care of the issues, huh?

Let's Talk Diesel

More than once someone said "I won't have a diesel because diesel fuel costs more than gasoline". I think; geez, I won't comment to this dude on that. But, then I wondered just how much more economical is a diesel? You see on TV how train locomotives haul one ton of freight 400-some miles on a gallon of diesel. And those big rigs on the road weighing 80,000 pounds getting 4 MPG. Could you imagine if those trucks were burning gasoline? one or two MPG?? Or, maybe how many gallons per mile?
Let's do some really fun math......
We'll compare a 3000 pound sedan running on gas and getting 36 MPG on the highway against the previous generation WV Jetta TDI diesel, also weighing in at 3000 pounds. Fair enough?
The Jetta gets over 50 MPG on the highway. In fact, we measured 54 MPG on a trip to Boston and back. Another trip we documented was at 52 MPG.
As of today the national average price of gas and diesel was $2.71 and $2.90 per gallon respectively. Gasoline has a heat value of 114,100 BTU/gal and diesel 130,500 BTU/gal. That's 14% more energy at only 7% more cost.
But there's more. A modern gasoline engine is 30% efficient, while a diesel is 40% efficient. Both efficiencies are rated at highway speeds in overdrive or 5th gear. Now, if we take those BTU/gal values and multiply out at .3 and .4 we get 34,230 BTU gal on gas and 52,200 BTU/gal for diesel. This is the amount of heat turned into work by the engines. The rest of the heat goes out the cooling and exhaust systems. The diesel delivers 50% more work than the gas engine.
Let's look at the MPG figures again, 36 for gas, 54 for diesel. Amazing, 50% better mileage.
What does that mean economically? For every gallon we burn in the diesel we go 18 more miles down the road than on gas. This equates to $0.95 saved per gallon. We paid $8000 for our used Jetta, can you figure out how many highway miles we would have to travel to pay for this vehicle?
Of course, there is the issue of pollution. A diesel is dirtier than a gas engine. (except the lastest generation of clean diesels) But, the pollutant outputs are measured per mile driven. More mileage, less pollutants per mile. If you add only 2-5% biodiesel, you sweeten the exhaust and is the best anti-wear additive there is. If this prevents your engine from wearing out sooner, just how green is it to prevent building another engine to replace it?
Americans don't like diesels like Asian and European countries. That why the selection is quite limited in the states. Most diesels are found in 3/4 ton and up pickups, few sedans.
When we drive down the highway, I can go a hundred miles before seeing another car that matches our mileage. Feels good, I get a little smug. Even a Prius can't catch us, except in the city, where it benefits from regeneration of electricity from braking.

More about the pond

Putting in the solar aeration system keeps me thinking more about the pond itself. We constructed the pond back in 1988 at the site of 2 conjoined sinks. With a little dozer action and managing to seal the basins, I had a receptacle for water to fill. The pond has 1.5 acres of surface, about 14 feet deep, and holds about 4 million gallons of water. Once full, it was barren. So I hauled in buckets of water and muck from surrounding natural wet places and streams. This I hoped would seed the water with all the lower life forms to support higher fish and animals.
After a while I stocked both small prey and smallish predatory fish. Over time I stocked minnows, blue gills, channel catfish, large mouth bass, and a few species caught in the Greenbrier river. All was going well except for the few Northern Pike I put in. I had to remove them because they ate EVERYTHING that moved.
After a couple years, I noticed cattails growing. At first I freaked out, surely they will overrun the place and will not match my image of the perfect pond (human version) It took a little while but I realized they could not grow in the deep part and by now would be a monumental task to remove them.
Then one Spring some Red Wing Blackbirds showed up and they stayed to nest. Apparently they prefer last year's dead cattails to build their nests. They are a joy to have around with their song and antics. Swifts and Swallows also came to nest nearby and show off their superb flying skills skimming bugs off the water in dive bomb raids. While that was happening bats flew high above them eating more insects. They live in our caves but come to the pond to eat. I suppose that is why we have only 3 or 4 mosquitoes a year that bug us.
Since then the pond is now used as a layover during migrations, we've identified a swan, black ducks, loons, buffleheads, wood ducks, mallards, geese, and some water fowl we're just not sure of. We also get visits by green and blue herons, osprey, and egrets. I believe they live on the river and come up to fish.
Soon I discovered mussel shells on the banks along with coon tracks. I wonder how the mussels would taste, so far, I don't know.
Animals come to drink like deer, coyotes, possum, and last week a fairly stout black bear during the dry spell.
Maybe this will be the best thing I ever did for the planet. Its certainly equal to the 70 acres of recovering future woodlands I have. Before there was just cows farting methane and a few species of grass and weeds. Now there is the habitat to support a very rich biodiversity that could otherwise not happen except for the pond. Making a small carbon footprint is to be encouraged, but actually adding something to the earth is the most satisfying thing one could do.

Alterra PV on Web

The final step in our home gridtie system is finally in place. The data from our microinverters and PV system is available nearly live on a website. The microinverter manufacturer provides this service at little cost and we can access at anytime. The data will accumulate for years to come and help to diagnose and see if we are hitting our yield targets. I invite you all take a look with a special visitor's pass:
http://enlighten.enphaseenergy.com/public/systems/GAMW5313
Be patient for all the data to load
Thanks

Renewable Energy Eyesore?

Over the past few years there's been quite a fracas over the industrial scale wind farm to be installed on our ancient mountain tops. (never mind entire mountains being removed not too far away) In typical corporate culture, Invenergy LLC had ulterior motives and omitted certain facts about the venture. Well they got caught omitting info and got punished by the Judge; they had to scale back the installation and get a license to kill bats.
I've been flipping back and forth about my feelings over the turbines. After all, they do represent one of the paths our country will follow for cleaner energy. Even my son, Ivan, posted a comment on my Big Oil Mess post. He said the sight of large scale RE sites pales in comparison to the gulf oil spill and the reckless/deadly mining of coal. I was surprised by his comment since he barely mentioned energy issues before.
While large scale RE growth will forge ahead, I think we all have the opportunity to do decentralized power generation and conservation. Modern RE devices are compact and the prices coming down. One can start on the smallest scale and build up over the years.
If you go to http://openpv.nrel.gov/ You can explore all the PV installations in our country that were reported to Open PV. No need to login just hit the explore section or search box. My brother Jeff and I put Greenbrier County in first place of all the WV counties. Shocking. It shows how one can make a difference.

Solar Community Brainstorming

I'm thinking about which solar fun project I will do next. The thought occurred that I should gather feedback from the viewers of my blog. If you have some unique and intriguing idea, respond with a comment or email me at bob@alterra-wv.com.
If I see something of interest, I might generate an engineered schematic for the archive or even build it for display.
Thanks in advance.

More Solar Fun

We will soon have an archive of schematics for solar projects on our website. Here is a sample of the first one showing plans for the pond aerator. This could also be used for fountains or irrigation.

A Wireless Solution

When we installed the PV grid tie array we used Enphase microinverters. These convert the DC to AC and there is one on each panel. Besides their other benefits, they can transmit data over the AC line about its performance. This data is accessible through an interface box simply plugged into any outlet. From there you may connect to your computer for simple monitoring or have a very comprehensive display and archive on a website that Enphase creates for you. Of course, this requires a broadband connection.
Our shop has DSL, however we are at the maximum distance from the phone company's DSL box at 19,000 feet. Our house is even further out making landline DSL impossible.
The solution? A point to point wireless bridge. If you don't have any hills in the way, you can beam two way data for up to 3 miles. It can even overcome a few trees in the way.
The cost is under $500 which is a one time charge. If we could get landline DSL it would cost us $49 forever. This thing will pay for itself in 10 months
Greenbrier Communications of Lewisburg, WV selected the hardware and will be configuring the system tomorrow. If all goes well, we will be posting a link for you to see our grid tie array in action.
Besides accommodating the data, we will have wifi in our house. This will be especially handy if I want to research a new recipe for dinner. All is right with the world.....

Pond Solar Aerator Online

I spent most of the day Saturday in the blazing heat to finally install the solar aerator I mentioned in a previous post. It is comprised of 4) 55 watt 12vdc solar modules, some 12-2 SO cable, a switch box w/a voltmeter and ammeter, 2) 12vdc bilge pumps rated at 1000 gallons per hour each, some 3/4 plastic tubing, stainless steel cage for a pump filter, foam float for the nozzles, and an old steel pipe for a bottom weight.
Once I was finally able to turn it on, the sun was already far to the west. However, the performance was impressive for the money I had in it.
The following morning, Tenley and I watched it slowly rise in power as the sun came over the trees and the mist burned off. She joked about having it computer controlled to make it dance. Well, later in the day, puffs of clouds raced in the sky and the wind picked up too. I thought, there is no need to make it artificially dynamic, the forces of nature were at the controls, diminishing the flow then gushing forth and the wind changing the water splash patterns.
Now, I wonder how it will change the pond's environment. Usually in the Fall you can smell an off-odor anaerobic whiff once and a while. Meantime, I will monitor turbidity and color of the water. It usually exhibits many state changes though the year, but I'm not sure what they mean. I can only take note of variations from previous years. Of course, there are many forces at work like wind, nutrients, or weather anomalies to throw me off.
I'll be looking into getting some UV resist flotation foam for the nozzles to make an island for turtles, frogs, or waterfowl to perch on.

Solar FUN

Here at Alterra our focus is usually on scoring a nice residential or commercial PV job. However, I recently realized there are those who would love to get their feet wet with some small solar application that would be both fun and inexpensive. Something that costs hundreds, not thousands. So, myself and friends
have been brainstorming fun projects one could do with solar energy. It could be practical or some visual spectacle.
Projects usually fit into three levels of system sophistication. (expense)
1) Direct drive: a properly sized array connected directly to a motor or pump. Just a switch and a fuse for safety. No sun, no run.
2) PV array, charge controller and batteries: This could run a low voltage appliance or lights with the reserve power for night use.
3) PV array, charge controller, batteries, and inverter: This system can provide auxiliary AC power for computers, TV, audio, small tools, and lights. Perhaps even a circuit in your house if you put in a transfer switch on that circuit.
I have two direct drive pieces on the property. One is a pond aerator using just panels, two submersible pumps (12vdc), some tubing and spray heads. The system should pump 1500 gallons per hour from the pond bottom (12 feet) and spray the water into the air at the surface. This will help oxygenate and turn over the bottom anaerobic water. Nutrient load and rotting vegetation causes this dead zone. (eutrophication) The other device is a simple solar whirlygig to attract passerby attention on US 219. Its a 180 watt panel with a 24vdc gearmotor spinning crabpot bouys. Most people think its wind driven.
Another application is as an electric cart charger. The blue cart has a single 60 watt panel on the roof. It acts like a range extender giving you more time between grid charges.
My brother, Jeff Hoffa, has a 60 watter on the cart and an aditional 120 watts on the roof. He made a charging station so he can plug in the cart for a total of 180 watts. He has no charge controller but he does have a volt meter mounted in the cart so he can manually control the maximum charge voltage. Since he does not use his cart as much as we do, he'll have a surplus. Since the battery pack in a cart is 48vdc and about 8 kWh of storage. Thats enough reserve to justify purchasing an inverter to use as emergency house power or use as a small single circuit supply.
Just think of the many uses and the fun it would be to construct a solar power kinetic sculpture or water fountain. We have several 12 volt and 48 volt panels available for $1.49/watt ( $80 something each panel) We will be developing small installations and contraptions as time goes on and posting some simple plans on our website. 'Til then dream something up and get a taste of solar.

The Big-Oil Mess

After watching the responses of BP on stopping the oil, I believe they will do anything except seal the well forever. If the estimates are right, that hole produces 4 million dollars a day if they could only trap it all and sell it. That's why the "relief wells" are being drilled hoping that when complete they could be the producing holes in the future. I guess they see they are going to need a lot of income to cover their asses.
The Feds on the other hand are slow to bring in the cavalry because it would hurt them politically if they asked for one more cent of tax payer's money. So, most of the effort so far has been to secure the funds from BP, and rightfully so. The states affected just don't have the budget.

A few weeks ago I emailed both BP and CNN with my idea of a possible solution. Drill a hole parallel near to the gusher and lower an engineered conventional explosive. Seal that hole and let her rip. If it is close enough to the gusher it would collapse the well like a soda straw. Even if it allows some leakage, the pressure would be reduced enough to install a new assembly on top of the well. I saw on CNN the other day where another solution is to use a nuclear bomb in the same fashion. Geez, a bit overkill and typical sensationalized reporting. I wonder if we could get a Daisy Cutter to fit down a hole?

Another thought I had was to capitalize on the spill. That goo must be worth something even if it is only good for asphalt. Enterprising boat owners could outfit their rigs to collect the goo. They could then haul it to a collection barge or something and get paid for their harvest. Similar to the incentives that drive people to collect scrap metal and haul it to the yard for a $ check. I think the value could even be subsidized for more incentive and still be ahead of the expensive, complicated contracts with skimmer outfits.

Computer Tip

ABOVE: THIS IS HOW MY COMPUTER USED TO RUN


I've had my Dell 4550 since 2003 and have been quite satisfied most of the time. After you run it over the years it slows down until you really notice how bad it is. I've tried all the system tools and Ad-Aware cleanup. Marginal improvements. The hard drive runs more and more transfering bits as you open and close programs. I thought I had to take to a shop and have them clean it up.
Then I talked to a tech about putting in more RAM. My machine has two 512 MB slots and only one card installed. I ordered another 512 for about 30 plus bucks. The performance was exhilarating, I went here and there and opened up many programs very quickly. Even the DSL seemed faster. I assume the delays were from the hard drive being a cache because the old 512 was swamped. If you have similar problems, fill up the RAM to the max. It will be the best money you ever spent.

Walk the Talk

We have been pursuing our renewable energy (RE) business for over two years now. We have had some nice solar PV jobs and also sold some components to offgrid families. While the interest in RE has grown due to the current administration's push to get off oil and the gross oil spill in the Gulf, individuals have been cautious about spending the money. The economic slowdown had come at the worst time for us to start the change.
Our personal plan was to put one 1800 watt grid tie array at our house. We had already put in a solar hot water system in the year prior. The solar hot water delivered the heat equivalent of 2.5 MWh (megawatt-hours) or 2500 kWh (kilowatt-hours) in one year of operation. This cut down on our grid use by over 25%. And for the last two years we have tackled numerous energy drains by replacing bulbs with CFLs and modifying our habits. Once we had reduced the majority of our wasteful use, we decided to invest the money in a PV array. Well, that one array turned into two because of an overstock of unsold modules.
As of June 8th we were officially net metering with the grid. Its quite exciting to see your meter read less than the day before. We hope to generate excess credits to use this winter when the sun is dim and we demand more power.
The decision to invest the money in RE is not based on economics but the feeling we had to get started on the road to carbon free energy. PV modules can last up to 60 years and the microinverters are rated at 331 years in mean time between failures (MTBF). My grandkids may one day be thankful that it was installed. I wonder what the electric rates will be in 2070?
RE is expensive, but so is a SUV, power boat, or some other neat toy. It came down to a matter of priorities, we will never have a big new gas hog. We are quite happy with our '02 Jetta TDI.