Solar Power update (part 8)

Written by peterkienle on February 3, 2010

(continued from part 7)

So here we are. February 2010. We had our solar array online for close to a year now.
What are the first year impressions of our life with a 1.2kw solar array in our front yard?

First, if you read the initial installment of my solar power posts you will notice that we built a post with a mount laid out to hold 12 panels. Because 200W panels aren’t cheap we only populated half of the array at first. These six panels were actually only 195W a piece, so to be correct they only add up to 1170w total. Since going online on February 11 2009 we made 1361kwh as of January 31 2010. The array has been producing power for just over 4010 hours. The power output during the course of a nice sunny day starts up around 8:30am (in the winter) with just enough wattage to turn the inverter on, typically 10 watts or so. Around 11:30am, when the sun clears our roof and hits the panels full on we are up to 800 watts which will quickly ramp up to 1050-1150 watts just around noon. It stays there until 2:30pm or so and slowly creeps back down to 50 watts around 5pm. On a sunny, cloudless day this will produce between 4.5 and 5.2kwh. In the summer we get up to 7.5kwh on some days. Of course if we have a very cloudy sky the power never exceeds 50 watts. January around here is like that sometimes. Total electricity usage in our first year with the solar panels was 14,320kwh. That means the panels contributed a little under 10% of the electricity used at our house.

As it turns out my installer, Alex Jarvis from Solar Systems of Indiana, helped me to sign up with a company by the name of Sol Systems which brokers SRECs (Solar Renewable Energy Credits). Based on the size of your system you get a yearly check for offsetting carbon output. I actually did get a check of a couple of hundred dollars for the first year. More than the $85 I saved on my power bills.

One other thing is that my system over-produces sometimes. In other words it makes more power than we use in the house and we get credit for it from our utility company. Unfortunately the credit that we get back is a little more than half of what we pay (we pay $0.0631 per kwh while we only get $0.03357 for a kwh that we feed back in.) Unless we overproduce during peak times – then we get a credit of $6.67 per kwh! During last summer we were actually able to still produce around 500 watts during evening peaks and it turns out it is a good time to turn off everything non-essential in the house for an hour to feed back as much as possible and get the peak time credit. If you can feed back half a kwh on 10 days in a month it adds up to a $40 credit on your power bill – pretty substantial.

Then, on January 5 2010 Alex came over and we added six more panels for a whopping 2370kw. This what our array looks like now:

Why, you ask, would I spend another $4,500 to add six more panels? I mean, I really *only* made about $285 last year. If nothing else happens, nothing changes, the price of electricity stays the same or the days become longer it will take me 33 years to break even, not counting at least one inverter replacement for about $2k in that time – and that calculation does already include a 30% tax break.

The answer isn’t exactly simple.

1) While looking at my power bills, we developed strategies to use electricity when we get it for free from the panels. We learned that dishwasher, washing machine, dryer, computer tasks involving multiple computers, etc. are better done during the day to use power from our solar panels rather than the grid.

2) With the help of a Kill-a-watt, which shows you how much energy a connected appliance draws over a given time, I was able to locate some real energy wasters in the house. For one, the dehumidifier in the basement is now turned off – that things sucks 300-400 watts! That’s about 3000kwh in a year! The solar panels make me really conscious about that stuff.

3) We have about 4-5 months in which we can actually overproduce and feed back power during peak times. With 12 panels we should be able to maximize our credits considerably.

4) While at the moment the 1/2 ratio between what we pay for a regular kwh ($0.0631) and what we get credited for ($0.03357) seems quite unfair, this will change eventually. Even in Indiana the law says utilities are required to pay retail rates for power fed back into the grid. It’s just that our power company is a coop and they are still excluded.

5) While our initial six panels were $1200 a piece and rated at 195w the new ones we put on just three weeks ago where $800 and are rated at 200w. So prices have dropped.

Today was really the first full day of sunlight since we installed the additional panels. Just before shutting down the inverter read 10.41kwh produced. And that’s pretty cool. Considering that on average we use about 39kwh in a day that’s about 1/4 of total electricity from solar. I am sure we will find more holes to plug in the walls and more ways to save energy. It should be an interesting year.

Solar Power bucket of salt (part 7)

Written by peterkienle on March 7, 2009

(continued from part 6)

After all the good vibes coming out of our solar installation I really need to reinforce something I knew long before I decided to spend almost $15,000. You can’t really predict the weather so we can only estimate our yearly average power production. Right now, in mid-February, on a cloudless day my PV system produces about 5.5Kw from sunup to sundown. Let’s assume during the summer we might get up to 8Kw per day. That’s an average of 6.75Wh and for simplicity round this up to 7Kw. If we have 365 cloudless days we would produce 2,555Kw in a year. At a cost of $0.105 per Kwh that should save me about $268 in a year. I realize that I can only get realistic numbers after monitoring my power output for a year but this amount is pretty close.

Here are two facts to consider about PV panels and alternative energy:

1) If I can produce all the electricity I need at my home during the day with my panels I will still need power after the sun sets. There is just no way around it, I will need the power from the grid until something better comes along. My PV installation will only cover about 15-35% of my usage unless I increase the number of panels four or five times and buy a few tons of batteries for storage. A system of that magnitude would cost me close to what I paid for the house.

2) Driving through my rural neighborhood I notice that many homes have outside lights. And more than half of them are on whenever I drive by. Day or night.
Now assume that’s a 200W bulb in there. Leave it on for 24 hours and your meter will move by a whopping 4.8Kw. That’s almost as much as my PV system makes at the moment in a day. If you leave that turned on 24/7/365 it will use 1,752Kw in a year. Now throw in another 100W for phantom loads such as VCRs, DVD players, cell phone chargers – all stuff that’s not turned on but still sucks a few watts while it is connected. All of a sudden you are looking at 2,628Kw per year that you could save just by switching that outside light off and investing in a few switchable outlet strips. That’s $263 in a year. Pretty close to what I save with my panels! And you almost get it for free!

There are a few reasons why I got the panels anyway.

1) In the long run – 20 years or so – I’ll break even and then the system still has 15-20 more years which will be savings in my pocket.

2) I wanted to learn how this is done. The digging, the wiring, all of it. There is nothing like some hands-on experience.

3) I wanted to do something else than just donate a few bucks to various political causes.

4) Not a week goes by without somebody stopping and asking about that strange thing in front of my house.

But frankly, unless there are some seriously cheaper and more efficient panels, a modern power grid and practical storage of overproduced electricity I don’t see how solar panels can make a significant impact in the overall energy budget. It’s a drop in the bucket as are many other alternative technologies at the moment. Of course many drops also fill the bucket eventually. But I think whoever claims solar power alone, or wind power alone can replace all the nuclear and coal power plants is delusional. At the same time it’s equally delusional to think that things will just go on as they have been.  Lots has to be done and everyone has to be more conscious about energy usage.

If nothing else, the PV installation in my front yard, and several others in and around my town show that things are changing. People are waking up. We should have paid attention after the oil crisis of the early 1970s. We could have altered our course a bit after 9/11/2001. Instead, we stick our heads in the sand and pretend everything is cool.

To conclude: For me the installation of a PV system in my yard is only a beginning and not the solution – but it can be a seed for a small part of a solution.

(continued in part 8)

Solar Power (part 6)

Written by peterkienle on January 28, 2009

(continued from part 5)

We’re still waiting for some insurance details to be cleared up. But at least finally the people from SCI-REMC, our electric utility, were here to do an inspection and a test run of the system. A nice, warm day (for January) enabled Alex and me to swing the mount to its proper angle of 45 degrees. Now, that really looks imposing. The people on my street finally know what’s happening.

It was very sunny that day and on the test run the inverter showed close to 1100 watts. That’s pretty close to maximum. I plan to keep track of electricity production once our system is officially running. The panels were pretty dusty since the ice, sleet and snow of the past two weeks weren’t able to slide off while the assembly was horizontal. Unfortunately the garden hose was still frozen so I couldn’t clean them.

We did get a new electricity meter. Pretty cool one. When we moved into the house in 1995 they still had to come to the meter, read the numbers and write them down. Then, a few years ago they installed a new meter which sends the reading wirelessly to the person driving by with a truck. This new meter sends its data through the power lines. It will measure how much electricity goes INTO the house as well as how much my PV system generates back into the grid. That probably isn’t a lot most of the time. It cycles through these five modes:
1. Kw – REMC delivered energy in 30 day billing cycle.
2. Kw – Peak or total consumer used kW over the last 15 minute period.
3. Kw – total energy consumer generated back onto REMC’s grid.
4. Kw – peak demand during peak period.
5. Kw – consumer generated energy back to the grid during peak period.

Plenty of numbers to be able to analyze how this will be working out.

I hope to be able to keep you updated on our status.

Solar Power (part 5)

Written by peterkienle on January 24, 2009

(continued from part 4)

Alright, so I’ve been a bit busy. Two weeks ago Alex came over with his friend Ken to put up the mounting brackets for the PV panels. For that they set up the scaffolding.

Here the panels are neatly laid out in our front yard. $1200 a piece! I sure hope none of my neighbors comes around the curve too fast with his truck and flattens these.

Now the electric connectors are put in.

All six panels are mounted! Even though both the brackets and the panels are not that heavy individually together it’s about 200 pounds sitting on top of the post. We didn’t know it at that time but the surface would stay horizontal for two weeks until the final inspection by the power company. Since this is a grid-tied system any electricity coming from the PV array that is not used in the house goes out, through the electric meter, onto the grid. In case of a blackout on the grid they need to be absolutely sure that the inverter will disconnect the panels from the grid so they can repair the line without having their workers fried.

The inside of the inverter while the last connections are made.

This is a pretty cool piece of engineering. It shows you how much power is produced in Watts, displays voltage, daily production (or more correctly from power-up when there is enough current from the panels to shut-down when the sun goes down). It also shows you how much carbon emissions were saved (or offset).

So now everything is ready to go. But we have to wait with the official commissioning until our electric utility people come for an inspection and some insurance stuff is cleared up. It’s like Christmas: You know where the presents are hidden, and even know what it is…..
(I did turn it on a few times just to see)

(to be continued)

Solar Power (part 4)

Written by peterkienle on January 17, 2009

(continued from part 3)

As a we are waiting to go operational I have some time to ponder the pros and cons of my $15,000 investment, alternative energies in general and solar in particular. Despite my feeling of doing something good for the environment and (maybe) for our bottom line I know that this technology is young, even though it has been around for decades, and like my computer the equipment I am installing might be outdated in a few years. Our calculations still show that we’ll break even after about 22 years. The system has a life span of 35-40 years. It is a very long term investment.

There is lots of talk these days about green energy and solar and wind are usually the first technologies mentioned. The problem with both of these is that you only get electricity when the sun shines or when the wind blows. There are really only two ways to have access to electricity when there is no sun or no wind: oversize your system and store surplus energy in batteries or a grid interconnect. Unless you don’t have access to the grid battery storage is really a bad idea. Electricity storage will have to be much more efficient than what is currently available to a homeowner. If you read Scientific American or MIT Technology Review or do a search on the internet you find many people doing great and promising research. Last summer I had a little test setup in my yard with a small solar panel electrolyzing water into oxygen and hydrogen. Nothing much came of it – maybe the plastic bag I used to collect the gases was leaky. More likely the electrodes were the wrong metal. At the same time I am not sure how safe I would feel if there was half a Hindenburg’s worth of hydrogen in a pressurized tank under my house. No storage then. But then each time the sun goes down you will draw power from the grid instead of your panels. So the power utilities can’t really scale down their power plants. Sure, if you work at home and most of your power is used during normal work hours you might be able to offset that with a solar array. But even if my whole street does what I do and nobody draws a single watt from the grid during the 4-8 hours of usable sunlight the power company still will have to keep their coal or nuclear power plant running. As far as I understand you can’t just flip a switch and turn them on or off. To my knowledge just gas power plants allow for relatively fast on/off cycling. At the same time changes in the electric infrastructure will take people like us into consideration.

Of course there are really cool proposals such as once we all have electric cars their batteries will function as energy storage while hooked up to the grid. One literally ‘cool’ idea I read about was to replace the current wires of the electric grid with superconducting material which is kept at very low temperatures by liquid hydrogen. Superconductivity means that electricity can flow through a conductor without resistance. Usually this is done by cooling certain materials to temperatures close to absolute zero. These would be pretty substantial ‘wires’ but they would function to deliver electric energy and hydrogen and could serve as giant energy storage reservoir. Not cheap, though. (September 2006  issue of Scientific American).

Then we also have the really huge stuff like solar power satellites in geosynchronous orbit around the Earth. Geosynchronous means the satellite is at such a distance from Earth that it appears to be hanging above the same point on the ground even as it is orbiting the planet at breakneck speed. Something like that could collect solar energy day and night. It would have to be huge (as in miles and miles of panels) and the energy would have to be transmitted to the ground using tightly focused microwaves or lasers. Since the US will lose manned orbital access for a few years after the Space Shuttle fleet is retired and NASA’s new rockets are not finished yet it doesn’t look too good for large cargo hauls to 36,000km orbits.

And, really why do I need to set solar panels up in my front yard if the payback is so long term that I can’t even be sure to still be alive to see it? Because it’s something that I can do now! This whole energy thing is made up of so many networked components that we can’t rely on one solution only. And we need to accept that it’s a moving target. Maybe more people would put solar panels or wind turbines up if you could buy them at Walmart. The fact that you can’t and that you have to actively make an effort to find skilled and knowledgeable people to help you with it forces you to learn about energy. I think that even if you end up not installing anything you will be much more conscious about your energy footprint and you will discover ways to waste less – or you stick your head in the sand (from what I understand ostriches don’t actually do this) and pretend that everything is fine and no change is necessary.

(to be continued)

Solar Power (part 3)

Written by peterkienle on January 3, 2009

(continued from part 2)

Together Alex and I started digging in my front yard in early October while our supplies were on their way. There was to be a big 3×3 feet hole, almost seven feet deep.

This was where our steel post was going.

The main hole soon got too narrow for two people and I started digging the 24 inch deep trench for the electric line going from the post to the house. You want to keep that as short as you can. The longer the cable the more power you loose on the way to the inverter. These are pretty hefty cables, too.

Of course, in the pretty Fall weather our two girls wanted to have a part in the fun.

Eventually the digging was complete. Most of the supplies had arrived. The first step was to set the post. This is one hefty piece of metal. Since we didn’t have a crane we devised a way to roll the 16 foot pipe with five people off the flatbed trailer, onto a four foot pipe of the same kind – so we could roll it towards the hole (it was a 20 foot post but since we needed only 16 feet we had one four foot piece left over). After the post was in the hole Alex started to prepare it for a concrete pour.

After that there were two days of electrical installations. There are actually two separate cable pairs going from the post to the house. Only one pair will be used at first. If we decide to add on a second row of panels all the wiring will be in place. These wires go into  the basement and connect to the inverter.

Made in Germany (I am proud to say). This piece of equipment turns the ~400V Direct Current (DC) coming from the panels into 110V Alternate Current (AC). After the actual solar panels the inverter is the most expensive piece of equipment needed. It’s also the one you will have to replace after ten years or so.

Then it got cold and we had to wait for the final paperwork from our power company. We will be the first grid tied solar installation of all their customers. I think they will watch us with great interest.

Currently (January 2nd) everything is ready to go. The panels are in the basement,

the mounting brackets are sitting under the deck,

and the post is waiting for a few days break in the weather.

(to be continued)

Solar Power (part 2)

Written by peterkienle on

(continued from part 1)

Alex, my solar assessor – his company is Solar Systems of Indiana – came over one cold winter day early 2008 with his Solar Pathfinder and a device called a Kill-A-Watt. The Solar Pathfinder is used to determine the best place on your property for a solar installation and how much sunlight you can actually harvest taking into consideration stuff like tree line and geographical location. The Kill-A-Watt is such a good investment that I got one myself and it makes the rounds through my friends’ houses. Do you know how much electricity your refrigerator uses in a day? Your computer? (with all attachments such as external drives and scanners etc. on?) How about your waterbed? Or your cell phone charger (which you probably leave plugged in even while you carry your cell phone around with you)? Even though I have been frugal in my power use all my life (and believe me, my wife and kids hate me for being after them all the time to turn the lights off when they leave the room), after Alex had measured the power usage of some stuff in my house I was able to cut back even more. In retrospect, the sheer process of measuring this stuff, and learning as you go, how much it costs to build power plants, etc. makes you very conscious about waste – and that’s a good thing.

Of course being the only Solar Assessor in my state means that this guy is busy. After his visit to my house he prepared a report for me. Pretty detailed. It turned out that my property had potential if we mounted the panels in the front yard on the ground or on a post – not on the roof. There are other considerations with roof mounting, especially penetration and possible weight issues. In the time from the assessment until Alex finally located some free time to start the actual planning of the installation (around June 2008) I went to a seminar at Indiana University dealing with many aspects of home solar technology. I learned a lot and thought for a while that I might actually learn some more, take a weekend seminar in Wisconsin, get certified and become the second Solar Assessor in Indiana. It didn’t go that way.

I spent most of July in Germany and then August, back home, writing down my energy usage to determine the base load to be able to size the system we were going to get. Base load is essentially all your power users which are on all the time such as refrigerator, computers, whatever. In the hot Indiana Fall, with the geothermal doing the AC,  I was able to determine the base load at just around one kilowatt. Then we started to devise a system.

  • 1)  We never had plans to go off the grid. I didn’t want an over sized six kilowatt solar array ($60,000) and a truckload of lead-acid batteries in the basement and then still face the possibility of running out of juice in the middle of February because of lack of sunlight.
  • 2) While utilities in Indiana are required to pay retail for what you overproduce and feed back into the grid our power supplier is a Co-op and they do not have to do that. They pay wholesale rates. So too much overproduction was not feasible. This pretty much sized our system at 1.2KW. Six panels, pole mounted, in the front of the house.

Then, in late September, came the $15,000 shopping list to the supplier. And early October Alex showed up at my house with a shovel and said: “Let’s dig!”

(to be continued)

Solar Power (part 1)

Written by peterkienle on

In the last year or so the term ‘alternative power’ has really come to the forefront again. High fuel prices, talk about peak oil and dirty coal. Good thing, too, because we need to talk about it. Especially during 2008 I kept getting emails from countless action groups and organizations such as the Sierra Club and the World Wildlife Fund mentioning it. The issue is actually on people’s minds….

For some reason it has been on my mind since I was a teenager. If you have read some of my other entries here you will be aware that big, complex engineering holds high fascination for me. All sorts of power plants fall into that category. From giant dams to nuclear power plants, from wind turbines to geothermal. And there are of course the more esoteric, fantastic or futuristic things such as fusion, solar power satellites, deep geothermal, tides, etc.

But what is an ordinary citizen supposed do to about all of that? Sure, you can contribute to some of the organizations who lobby for clean power and oil independence in Washington. But still, somehow somebody has to do the dirty work, build something, make something work. Only scientists get to do the cutting edge stuff. We consumers just have to wait until product becomes available at our local hardware stores – sometimes ten years after you first read about it in Scientific American, often never.

Here’s the first part of our ongoing story:
We bought our home in 1995. After paying rent all my apartment-life it came as quite a shock that not only could you do stuff to your house and garden but unless you wanted to call somebody to fix that drain or dig that hole YOU had to do it yourself.

When we moved into the house we had a brand new gas furnace installed. It was fairly efficient but a few really cold winters convinced us that some other heat source might be more economic. I spent the first half of 2001 looking for a local contractor who knew how to install a geothermal heating & cooling system. Around May I found somebody – 90 minutes drive south. In August, in the course of a few days, the system was installed. We spent a bit over $10,000 on it but it works much more efficient than the gas furnace. Since then the gas prices have gone up even more and my latest calculations show that we did break even already.

After that I started seriously looking into solar power. But, really, in the first years of this decade nobody wanted to hear about it. My car mechanic and my dentist both told me they had solar panels installed in the early seventies after the first energy crisis. Their experience was not a good one – non-standardized systems, no spare parts available and nobody close by to maintain it. So, for about six or seven years I kept looking around for somebody to help me. Sure, there was (and is) plenty of the needed material for sale at places on the internet. There are plans, layouts, articles. But I really wanted somebody to come to my house, look at the property and tell me whether this was feasible or a pipe dream.

In late 2007 there was a little press about a few houses being built in the city of Bloomington, IN (my hometown). Some of these houses had solar panels on their roofs. Through the real estate company I found the person who had put these on. And guess what. He lives about a mile from my house, is a well known rock drummer in town and happens to be the only certified Solar Power Assessor in the whole state of Indiana.

(to be continued)

Copyright © by Peter Kienle