So, you live in Maine. You consider yourself independent, hard working, well informed and looking to the future. You and your family are looking to become more energy efficient and lower your carbon footprint on our planet. Youve changed your light bulbs to compact fluorescent's. Youve changed your appliances, one at a time, to the most energy efficient ones you could find and you make sure the kids turn off lights and shut off power on games and computers when theyre not using them. Youve changed those energy hogging electric heater, electric stove and electric hot water heater to more efficient propane models, which also are cleaner from an environmental standpoint. You even bought an on-demand type water heater to really cut down on wasted power from keeping a tank of hot water heated all day. Whats next?
You, and many others in Maine, are taking the steps we need to be more electrically energy independent in our state. I would suggest that at this point you would be excellent candidates for a solar electric (photovoltaic or PV) system.
There are basically three types of PV system. One, the simplest and most inexpensive (although that is a relative term) is the straight utility intertie. This is a series of solar panels which connect directly to an inverter, through various safety devices, which then connects to your main house panel or meter, and finally to the utility. The utility, either Bangor Hydro or Central Maine Power, then credits you for the power you make from your PV array. For every kilowatt hour your household uses, they subtract one from what you have sold them. This is referred to as net metering. This type of system is used most in areas where the power rarely goes out or the user decides to use a generator for times of utility blackouts. Because of its lack of need for maintenance and straightforward installation, as well as the lower overall price per installed watt, it is the most popular type of PV system in use right now.
The second type of system is the utility intertie with battery backup. This system incorporates batteries into the system but also can sell excess power back to the utilities. The inverters used in these systems differ from straight utility intertie type inverters, but provide people with almost instantaneous backup power in the case of power outages. Because more components and the addition of batteries are necessary this system can be 20%-40% more expensive than the first type of system we talked about. It is easy to maintain, usually only needing to top off the batteries with distilled water three or four times a year. On this type of system we plan battery storage for the critical loads in the home, typically water pumps, refrigerators and some lighting, to lessen the size of the battery bank but still maintain the homes ability to remain livable in cases of power outages.
The third type of system is one we install in many backwoods locations where the utility grid is far from the home. These systems are referred to as off grid. They generally provide the homeowner with the most independence, creating up to 100% of the homeowners electrical needs. In most cases the homes will also have small backup generators installed in case of long periods of cloudy weather which we can sometimes see in November and December particularly. We have over 120 of this type of system installed in Maine alone, some for as long as twenty years. These are the ultimate in energy independence, but are the most expensive to install and require the highest degree of energy efficiency in the home.
But, you ask, does Maine have enough sun for me to run my home? The short answer is yes! Many places in Tennessee, Pennsylvania, Ohio and so many other places in the country have less available solar insolation than we do in Maine. Solar Insolation is defined as the amount of solar energy that strikes a given area over a specified time. We in Maine have an average of 4.3 usable sun hours over the year, daily. It can be as little as 2.9 hours of sun in November or as high as almost 6 hours in July. A properly designed system, properly installed, can utilize this solar exposure to its maximum capabilities. It is possible to start small, say, with a system for as little as $5000.00 which can be increased as time and budget allow. It is important to have a long range view of where you want to go when you start the process of working with your solar designer. Remember that you cant add new batteries to an old battery bank, if you decide to go with an off grid or battery based grid intertie system. Try to design the system for future expansion from the start, even if your expansion is only in small increments.
There are so many ways we can lessen our impact on our planet and in our beautiful state and they are all incremental. Simply working patiently toward our long range picture of where we want to be in the future is the best way to get there. Whether its with the car we want (or dont want) to drive or envisioning our electrical independence with our own off grid solar electric system ,the plan is the same. We have installed over 300 systems in Maine in the last twenty years with all our customers very satisfied. Many did not think they could achieve the independence they feel but are now avid supporters of the technology and the concept. Remember, living with solar is different and requires a bit of change in the lifestyles of many, but change is not sacrifice and can be exciting, even exhilarating. Going solar typifies the spirit of Maine and the Yankee independence we are known for. It is the best of both worlds when we can be ourselves and help the planet to be cleaner and healthier.
Daryl DeJoy is the owner of Penobscot Solar Design and is certified in Advance PV Design as well as a NABCEP certified PV installer. He has been designing and installing solar electric systems since 1988. For more info go to www.penobscotsolar.com or email Daryl at firstname.lastname@example.org