Extra Power

Since we are living “off grid,” we aren’t able to send extra electricity we generate to the electric utility. So, what do we do with extra power? Right now, we are able to run an air conditioner, dehumidifier, and several other appliances when the sun is shining. I’m planning on adding a DC water heating element to my hot water tank so that when the batteries are full, the extra power will be stored as hot water, thus reducing the use of propane for the tankless hot water heater.

What are you doing with your extra power?

New Friends

One of the things I enjoy most about being in the renewable energy business is meeting people and making new friends. We just finished an installation for a couple in New Hampshire, and their friendliness and hospitality made the job easier and more enjoyable. I have found that most people that are committed to renewable energy have a great outlook on life and are wonderful people.

Beginning of the 2011 installation season

We just completed our first PV installation for the 2011 season, a 2,300-watt grid-tie PV system. It was nice to get back to work like this, and we made the most of two kind-of sunny days to complete the installation. We got a bit of sunburn the first day, but it was cloudy enough to not be a problem on the second day.

We learned a few things on this installation. Working on a roof with little to no extra room around the edges is hard. We had to be extra careful when installing the last two modules, since we didn’t have much to stand on. But we got it done safely, and we think it looks pretty good. What do you think?

 

Cloudy days

We ran the generator yesterday evening for a couple of hours to charge the battery bank – the first time we had run it since early January. The culprit was a combination of a string of cloudy days with little solar exposure, and a number of power-hungry appliances that had to be operated, like the washing machine, vacuum cleaner, and gas oven. That, combined with a light table for starting seeds and an incubator for starting chicks, caused the batteries to get quite low. However, if I had known today was going to be as sunny as it was, I may not have run the generator. But, you just never know what tomorrow will bring. At least we are set for a few more days.

PV or SHW?

Which is a better option – solar electric (PV) or solar hot water (SHW)? Well, it really depends on your situation. If you want to recoup your investment quickly, SHW is a better option, as you can save enough in hot water heating costs to pay for your system in three to five years. If you want a long term investment, PV is a better way of making a decent return on your money. The cost of electricity will likely only increase, and the electricity you generate will always be fairly constant year after year. Considering any incentives that may be available, your investment begins to pay immediately.

So which is a better option? You decide, and give us a call to see how we can help you.

Backup Power

Did you lose power during the last storm? We didn’t. As a matter of fact, the only reason we knew power was out in the neighborhood was our internet was down. And we had to start our neighbor’s generator for them (they were out of town). And we had to check on another neighbor’s house. Some of our neighbors were without electricity for more than 24 hours.

If you were without power, or frequently lose power for long periods of time, you might want to consider installing a solar back-up system. If designed and installed correctly, you may not even notice when the power goes out. And when you are not using your solar electricity to power your loads, you can send it back to the grid for a credit on your electric bill!

Call us if you would like to explore this option for your home.

Cold sunny days

If you have solar PV and live in New England, you are probably making a lot of power from your solar PV system today. Where we live, it has not gotten above about 5 degrees F all day, and we have been making a lot of power. This is because PV modules are more efficient in cold weather, and have higher output.

When designing a PV system, it is imperative that the increase in output during cold weather is considered when selecting an inverter and overcurrent devices to ensure that this equipment can handle the potential increase in power. If these devices are undersized, it could cause the system to shut down when it has the potential to make significant amounts of power. Besides, what else is there to do on a cold New England day but watch your meter spin backwards?

Fall Maintenance

Now that daylight savings time has ended, I am noticing how few hours of sun we are getting. It reminds me that I should adjust my solar panels so that I capture all of the sun that falls on them. So if you have adjustable mounts for your solar array, now is a good time to make seasonal adjustments. If you live north of the equator, your optimum angle from horizontal is your approximate latitude multiplied by 0.9, plus 29 degrees. The optimum angle for summer is 52.5° less than the winter angle. You can find more complete information here: http://www.macslab.com/optsolar.html. Let us know if you need help with your adjustments – we will be happy to assist.

Off-grid living

One of the things I enjoy about off-grid living is having to work with what God gives us by way of weather. As an example, since we make all our own electricity, I wanted to not use any to move water. Thus, we installed two wells (actually cisterns to collect spring water) a few years back that are higher than the house so that the water would flow by gravity to the house. When we installed the water supplies, I had no idea of the elevation difference between them and the house, but I hoped that there would be enough pressure to make the water flow where we wanted it. To my surprise, our highest well produces about 107 psi – more than enough. The second well, which I had to connect to the house during the drought this summer, produces about 60 psi. Using a GPS to measure elevations, it appears the the upper well is about 250 feet higher than the house, and the lower well is about 120 feet higher than the house. But what difference does that make when the wells run dry? Thus the installation of a third cistern this summer.

This new well is located about 1300 feet from the house, and produces about 45 psi – certainly enough to give us water throughout the house, even in the attic where the hot water tank is located (more on that later). However, the boys are not happy using this well, since “there is no pressure” when showering.

So why did we go this route for our water supply? It cost about $2500 to install the new cistern, and took me at least 40 to 60 hours to dig the hole, install the cement dry well, lay out the pipe, trench, and bury everything. Was it worth it? I could have hired someone to drill a well close to the house and installed a typical water system, and had no more concerns about water or water quality (surface water supplies are not always pristine).

Consider the amount of electricity that I would have had to generate to use that water. We probably use a couple of hundred gallons a day. Assuming that we could use a small submersible pump that only draws six amps continuous (up to 36 amps on startup!) at 230 volts with a large tank, we are still going to use a significant amount of electricity. If I lived in Arizona, this might be feasible, as I would likely make enough power during the day to allow me to run this pump. But, alas, I live in Vermont, where we don’t get six hours of sun on average each day. So gravity fed water works for me, and with the three sources, I think I should be set, even when we get another drought (I had plenty of water in the new well even during the worst part of the drought).

If you are planning for going off grid, you may want to consider how you will keep water flowing into your house. This seems to be a major issue for people when they lose power. Having a backup plan for maintaining your water supply when the power goes out can make the difference between a minor inconvenience and a major headache.

Rain, rain, go away…

It’s been hard to make electricity with all the cloudy and rainy weather we have been having. But it hasn’t been too much of a problem since our charge controller broke on Friday. But if it were working, just how much power can be made under cloudy conditions? Well, the new solar panels (UniSolar PVL-124) on the roof, we should be able to make at least a few amps during the day, unless it is severely overcast. The UniSolar modules are flexible laminates, and are supposed to be better at scavenging power under sub-optimal conditions. These modules are typically applied to standing-seam metal roofs, so options for using these modules are limited. But if you have a standing-seam metal roof that faces south, these may be just right for you, and may help you make power, even when it is raining.