Solar Energy, Solar Power

Maine and the federal government provide fairly generous rebates for families who choose to install solar panels as a way to reduce their consumption of traditional sources of electricity or heat. You can learn more about the rebates at Efficiency Maine.

We decided to find out what it would take to use solar energy to power and possibly heat our home. We have a south facing home which gets lots of sun all day. We contacted a company in Maine that installs solar panels and integrates the power produced by the panels into your existing electrical panels.

We learned that there are two thing we can do:

1. We can use solar panels to produce electricity. The cost of installing the solar panels for electrical power is pretty steep and may not be the most efficient use of solar panels for a home in Maine. Because Maine has long winters and the sun is low during the winter months, we probably would achieve much, in terms of savings.
   
2. We can use solar panels to produce hot water. The use of solar panels to produce hot water turns out to be a much more efficient use of solar energy. We learned that using solar panels to produce our hot water would save us about 250 gallons of oil per year. That is about $500 per year at today's curren price per gallon.
   

We are still considering both options, but the latter option makes the most sense for now. Although we really want to do what it takes to reduce our footprint on the Earth, we are realistic and unfortunately have a pretty limited budget. Anyway, the quote we received is below. Hopefully, this will help someone who is considering installing solar panels.

In almost all cases here in Maine, the most economic (least expensive up front as well as fastest payback) of these is the solar domestic hot water system. The reasons for this are simple; first, domestic hot water is a year round load, so you can take advantage of the sun all year round; second, the typical existing systems for heating hot water are incredibly inefficient, so eliminating this load is ‘low hanging fruit’ in terms of energy savings. In your case this is particularly true because of the type of oil boiler that you have. As you no doubt know, your oil boiler stays hot all summer long, even though there is no heat demand, only to be available to produce hot water when you need it. This is an incredibly inefficient operating mode. If your household is typical, you probably consume between 200-250 gallons of oil each year in the non heating season. Of that 200 G of oil, only about 40 G is actually heating water, and the remaining 160+ is just heating the boiler, the chimney, the basement etc. Like I said, this is an inefficient way to heat water. So our goal, when designing a solar hot water system, is to be able to eliminate as much of this waste as possible. As you can see in the attached proposal, I’ve proposed a couple of different ways to do this (see attached).  

 

The other good solar option for your home is a grid tied photovoltaic system (or solar electric system). These systems are typically somewhat more expensive to install than solar hot water systems but they have a very long life expectancy (25 years+) and require zero maintenance or action from the homeowner whatsoever. They simply produce clean, solar electricity whenever the sun is shining and feed it to the buildings load center. If there are loads in the house, the electricity will go to powering them. If not, it will go out backwards through your meter to power your neighbor’s house and you will get a credit for that electricity on your next electric bill. Please see http://www.energyworksllc.com/electricity.html for more information about these systems. I did not come up with a detailed proposal for a PV system because I didn’t actually get on your roof to get detailed measurements of just how many solar electric panels will fit in that space. By inspection, I think we could most likely fit 1.9 kW of solar electric system on your garage roof. Depending on how frugal you are with electricity, this should provide between 40 and 70 % of your electricity consumption per month. A system like that would cost roughly $16-18k installed and would be eligible for a $2k federal tax credit. If this is something that interests you, let me know and I will swing by again to get a detailed measurement of that roof and then I will send you a firm proposal for the PV system as well.