Bulletin #7217, Maine Home Energy: Options for Home Heating Fuels and Energy Systems — An Overview
Developed by Extension Professor Donna Coffin, University of Maine Cooperative Extension. Reviewed by Extension Professor Kathy Hopkins and Extension Professor Gleason Gray, University of Maine Cooperative Extension. Additional review by Solar/Wind Program Manager Richard Fortier, formerly with the Maine Public Utilities Commission.
Table of Contents
- Wind Power
- Incentives for Energy Efficiency and Alternative Energy Systems
- Comparing Home Energy Options
There are many considerations when thinking about how you will heat your home or provide electricity. Start by asking yourself the following questions:
- Are you planning to build a new home and install a system that can be built into the plans, or are you planning to retrofit your current home to accommodate a change in heating fuels or methods?
- What economic or environmental values are important to you and your family?
- What is the cost for the system, as well as the cost to run the system?
- What effect will the system have on the environment?
- Will you be utilizing a current resource?
- Are service and repair people readily available?
- What are the physical capabilities and time availabilities of the people who will be living in the home?
- How will the system affect your home’s resale value?
- How much capital do you have to install the system or make changes?
- Are there tax credits available for the system?
Before installing a new heating or energy system, it is important to install all possible energy conservation improvements in your home. This ensures that the heat or energy you produce is not lost through poorly insulated walls or inefficient appliances.
Oil, propane, and natural gas are commonly used in Maine, with oil being the leading source of heating fuel in 80 percent of Maine homes. As a result, a huge infrastructure has been built to provide timely delivery of fuels and timely repair services. It is easy to find competent people to install and maintain oil, propane, and natural gas systems. They are easy to use, require minimal maintenance by the homeowner, and, with the exception of natural gas, are not site-specific. These systems have low fire potential and insurance companies recognize these fuels as common sources of heat. Carbon emissions are very low for these fuels, especially when used in new fuel-efficient furnaces or boilers. The chance of exposure to carbon monoxide gas is also low with these fuels, as long as the furnace or boiler and associated flues and chimneys are in kept in good repair and serviced annually.
These are not renewable sources of energy. The burning of fossil fuels increases the carbon emissions that contribute to global climate change concerns.1 Use of these fuels increases your carbon footprint. Also, the ever more volatile cost of fuel oil can put a severe strain on heating budgets.
Wood and Other Renewable Fuels
Wood, in the form of logs, pellets, or other formed wood products, is a renewable source of fuel, in that trees regenerate or regrow. There is some speculation that if all homes were to use wood-based fuels, our forests could be depleted. But as long as the wood is harvested sustainably, this source of fuel is renewable.
Current wood-burning technology requires at least twice-daily stoking of the firebox with about forty pounds of wood or pellets, although the pellet industry is working on a bin system that could be filled with several weeks worth of pellets. With three sites manufacturing pellets in Maine, it appears that availability will not be a problem.
Wood stoves, fireplaces, and wood furnaces account for most home fires during the heating months in Maine. 2In many cases, home fires result from chimney fires, improperly installed or maintained woodstoves,3 or flammable materials placed too close to a wood-burning appliance.
Homeowners with wood-burning heating appliances should understand how to minimize creosote buildup in their chimneys. It’s important to remove any flammable material from the vicinity of heating appliances to prevent fires. (Outdoor wood furnaces, which are separated from the home and distribute heat through a hot-water system, avoid this danger.) Insurance companies often increase homeowner premiums for homes heated primarily with woodstoves because of the added risk.
Other considerations when thinking about wood heat:
- Homeowners who cut their own firewood should learn and practice safe chainsaw operation.
- Most woodstoves can be used when the electrical power goes out. However pellet stoves will not function properly during a power outage, nor will any stove that heats water for a circulating hot-water system.
- The Maine Office of State Fire Marshal standards require wood stoves to have a chimney separate from that of any other heating appliance.
- Sizing your biomass boiler to fit your needs (see Bulletin #7230).
A few folks in Maine have corn-burning stoves that burn dry shell corn. Generally the corn is grown in the Midwest and must be shipped to Maine. Bulk storage of corn may be a challenge for some homeowners, but corn is also sold in 40- to 50-pound bags that might be easier to store. Shelled corn is usually available at feed stores and can be purchased in bulk. Note that corn costs have become very unpredictable in recent years.
Some homeowners in Maine have experimented with ground-source heat pumps. In winter, a heat pump is essentially like a refrigerator circulation system that removes heat from one place (the ground) and transports it to another (your home). In summer, the pump uses the even temperature of the ground to cool your home. A heat pump is two or three times as efficient as an electric heater or air conditioner.
Before 2008, we in Maine had to bury pipes in the ground to take advantage of heat pump heating systems, while south of us homeowners could use air-source heat pumps to heat and cool their homes without a ground piping system. New technology has recently come to Maine that enables air-source heat pumps to heat and cool homes.
Because this technology is new, installers and service people are in short supply. This means that the homeowner may need to take some responsibility for understanding and maintaining such a system. There is no need to store any fuel for the system as long as you are connected to the power grid. The system can be connected to either a hot-air or a hot-water heating system. Before considering a heat pump, be sure to insulate your home well, as the cost of the electricity to run the compressor is substantial. Installation costs can also be expensive for these systems.
Solar thermal heating
The sun can provide some heat to your home, even in winter, if the home is oriented toward the south—with plenty of south-facing windows—and has some sort of system to store heated air or water. Passive solar homes are designed with little or no window glass on the north side of the home, large energy-efficient windows on the south side, and a large amount of thermal mass (water tanks, concrete floor, etc.) placed so that it is warmed by the sun during the day, and then stores and releases the stored heat during the night.
Needless to say, it is easiest to plan passive solar heating into a new home than to retrofit an older home. You need to have a suitable site that is oriented toward the south and has an unobstructed view of the sun all day in the winter. It should not be shaded by trees, buildings, or hills.
Passive solar homes, depending on their design, can have extremes of heat and coolness that may be difficult to adjust to. In addition, some type of backup heating appliance is required to warm the home during extended periods of cloudy weather. Insurance companies will look for backup systems that prevent the water pipes from freezing in solar homes.
Older homes may be more easily retrofitted with active solar thermal systems. Active solar thermal heating systems use electricity to transfer solar-heated air or liquid directly into the home or into storage for distribution.4 However, systems that heat the whole home can involve quite a bit of expense. The number of repair and service technicians for solar thermal systems is growing, but homeowners will need to take some responsibility to understand and maintain solar thermal heating systems. Homeowners may also decide to install an active solar hot-water heating system for their domestic hot water, at a more reasonable expense.
Using heat energy from the sun is very beneficial to the environment and can reduce your carbon footprint, reduce your dependence on heating fuel, and reduce emissions from wood smoke.
Currently 76.5 percent of public electric power in Maine is generated by gas (27.9 percent), nuclear (25.8 percent) and hydro (22.8 percent) sources. The remainder of our power is generated with coal (9.8 percent), oil (5.7 percent), municipal waste (4.2 percent), co-generation (2.3 percent), and biomass (1.5 percent). While gas and nuclear are cleaner burning than coal, they still negatively affect the environment and require Maine to be dependent on out-of-state fuel sources for power.5 But distributed power sources are changing in Maine.
The Maine Public Utility Commission publishes a list of green sources of electricity, primarily wind and hydro power. Homeowners can elect to use power from these green sources by contacting their power company and specifying where they want their power to come from. This may come at an additional expense, but it could prove to be less expensive than installing and maintaining your own solar or wind power generating system.
Solar Power (Photovoltaic)
Photovoltaic panels are expensive to install. If you want to be connected to the grid and qualify for tax credits, you must have photovoltaics set up by certified installers. While there are a growing number of service people, availability can vary throughout Maine and in the event of emergencies there may be a time lag before a service person can assess problems and repair systems. As a result, homeowners with photovoltaic systems need to be ready and willing to do some of their own troubleshooting, servicing, and maintenance. More regular maintenance is required for systems with battery backup.
There are a number of steps that homeowners planning to use solar electric systems can take to make the most effective use of photovoltaic energy:
- Use the most energy-efficient appliances.
- Use appliances that utilize other sources of energy, for example a gas dryer, a gas stove, a gas or solar water heater, and a wood-burning heating appliance.
- Buy a super-insulated refrigerator.
- Install an active or passive solar home heating system
- Manage electricity use according to times of generation (sunny days).
- Clear trees and shrubs that might shade the solar array.
- Assess your site for PV potential. The In My Backyard tool estimates the electricity you can produce with a solar photovoltaic (PV) array (National Renewable Energy Laboratory, PVWatts® Calculator).
Like other small renewable energy systems, home solar-electric systems can be “off-grid” (independent of the public power grid) or “grid-tied” (connected to the power grid).
Many remote homes with no access to the grid rely on arrays (collections) of photovoltaic cells to produce electricity from the sun and power electric appliances in their homes. When solar power is the only source of electricity, solar-electric systems must include enough battery storage to provide power when sunlight isn’t available, during cloudy days and at night.
Some homeowners install solar arrays to power some of their electrical needs, and yet are still connected to the grid. During the day, any unused electricity generated by the solar array is routed back to the power grid, and through “net metering” is banked with the electricity distributor, offsetting your grid-based power consumption and bill. The grid supplies power during cloudy days or at night. When you use more power than you generate, you will get a bill from the power company. Current pricing structures to purchase and install photovoltaic systems may make this energy source a financial challenge to individual homeowners.
Using electricity generated from the sun is very beneficial to the environment and can reduce your carbon footprint, as well as reduce our dependence on fuel for electricity generation from outside of Maine.
There are fewer home sites in Maine that are suitable for wind power than there are for solar applications. Homeowners need to assess their site thoroughly to be sure it makes sense for a wind turbine. One recommendation is to erect a temporary tower and collect wind data for a year so that you can determine the appropriate turbine size to install. You can find more information about small wind electrical systems and evaluating your site for wind power from the U.S. Department of Energy, and from the American Wind Energy Association and National Renewable Energy Laboratory. To identify wind energy potential, visit National Renewable Energy Labortory.
You may also need to look at ways to reduce electricity demands in your home. Consider replacing appliances with super-efficient versions, or replacing electrical appliances with those that use other sources of power. Consider your space-heating system, water heater, range, etc.
Also, remember that not everyone may appreciate a wind turbine in the neighborhood. Some towns have ordinances and zoning regulations for wind turbines, so find out if you need to get appropriate permits to install a system.
If you plan to connect to the grid, you will need a licensed electrician to install the system and the connection to public power. In addition, even though wind turbines are becoming more and more reliable, they do require regular servicing. It is important that you, the turbine owner, understand your system as well as your personal limitations. The number of installation and service technicians is growing but when something goes wrong, or when it is time to maintain the turbine, the first person going up the hundred-foot tower might be you.
Initial cost per kilowatt hour for the turbine, tower, inverter, and other associated equipment is relatively very high for small home models when compared with large commercial wind systems. If you are not connected to the grid, you also need to plan for battery backup for times when the wind isn’t blowing, or when it is blowing so strongly that the rotor has to be stopped.
Using electricity generated by wind is very beneficial to the environment and can reduce your carbon footprint, as well as reduce our dependence on electricity from outside of Maine.
Some homeowners in Maine with access to flowing water on their property may be able to generate on-site hydropower. Most home hydro systems would be classified as microhydropower systems—those that generate up to 100 kilowatts (kW) of electricity.6 The amount of power generated is related to the “head”—the vertical distance the water falls from a pond or other containment area to the turbine—plus the “flow”—the volume of water that flows through the turbine. Information on microhydropower systems is available from the U.S. Department of Energy.
Like wind and solar systems, microhydropower systems can be grid-tied or off-grid. For the most part, homeowners need to be ready and able to take the lead in designing, installing, and maintaining a microhydropower generation system, with the assistance of an electrician, if they plan to sell power back to the public power grid.
Several local and federal government agencies will need to be contacted to get appropriate permits to install water containment dams or other structures. Also, other permits are needed to alter the natural flow patterns of brooks or streams. Keep in mind that recently several large hydrogeneration dams in Maine have been removed from river systems to restore water flow for the benefit of native fish and other fauna.
While hydropower can reduce your carbon footprint, it can alter the flora and fauna environment.
Permits and water rights
When deciding whether to install a microhydropower system on your property, you also want to know your local permit requirements and water rights.
Whether your system will be grid-connected or stand-alone will affect what requirements you must follow. If your microhydropower system will have minimal impact on the environment, and you aren’t planning to sell power to a utility, there’s a good chance that the process you must go through to obtain a permit won’t be too complex.
Locally, your first point of contact should be the county engineer. Your state energy office may be able to provide you with advice and assistance as well. In addition, you’ll need to contact the Federal Energy Regulatory Commission and the U.S. Army Corps of Engineers.
You’ll also need to determine how much water you can divert from your stream channel. Each state controls water rights; you may need a separate water right to produce power, even if you already have a water right for another use.
For more information, see state and community codes and requirements for small renewable energy systems.
Reproduced from the U.S. Department of Energy EERE, “Evaluating a Potential Microhydropower Site,” Making Clean Electricity, Energy Savers.
There is a federal tax credit of 30 percent, with no cap, for the cost and installation of renewable energy systems. This program runs until 2016. Generally these are commercially available systems that have been third-party tested and rated.
At the state level, Efficiency Maine has several incentives for residential energy improvements. To get details on the programs, go to Efficiency Maine At Home.
To view all energy incentives through state and federal programs, go to the Database of State Incentives for Renewables & Efficiency®.
The following chart provides a visual comparison of attributes of various fuels and heating methods. There are no magic bullets to solve the home energy use dilemma, but there are a lot of options. You must analyze your family’s needs and willingness to adjust to the different heating and energy system requirements for regular use.
As you look through this chart, you will notice that no one fuel or system is perfect; they all have a downside to their installation or use. Be an informed consumer and investigate all the benefits and drawbacks of a new heating fuel or system before you install it in your home.
1 – This fuel or method has this attribute.
2 – This fuel might have this attribute.
3 – This attribute minimally applies to this fuel or method.
NA – This attribute does not apply to this fuel or method.
|Fossil Fuels||Renewable Fuels||Electrical Energy||Alternative/Green
Fuel Oil Hot Air
Fuel Oil Hot Water
Wood Stove Stick
Wood Pellet Stove
Outdoor wood stove
Passive Solar Heating
Active Solar Heating
|Many installers & qualified service technicians available||1||1||1||1||1||2||2||2||1||3||2||2||2||3||3|
|Fuel delivery available & easily secured in Maine||1||1||1||3||1||1||2||1||1||1||NA||NA||NA||NA||NA|
|Fuel or power easily stored on premises||1||1||1||NA||3||3||3||3||NA||NA||3||3||3||3||3|
|Fuel storage on premises requires large area||3||3||3||NA||1||1||1||1||NA||NA||1||2||2||2||2|
|Useful with other household applications and appliances||NA||NA||1||1||3||3||3||3||1||NA||NA||NA||1||1||1|
|Chimney for exhaust of gases required||2||2||2||2||1||1||1||1||NA||NA||NA||NA||NA||NA||NA|
|Direct vent system for exhaust of gases required||2||2||2||2||3||2||2||3||NA||NA||NA||NA||NA||NA||NA|
|Duct or hot water system needed to distribute heat||1||1||2||2||2||3||3||1||2||1||3||2||1||1||1|
|Each room individually controlled||2||1||1||1||3||3||3||3||1||2||3||2||1||1||1|
|Can be used as a supplemental source of heat||1||1||1||1||1||1||1||1||1||2||1||1||2||2||2|
|Homeowner maintenance requirements (monthly)||2||3||3||3||1||1||1||1||NA||3||3||2||1||1||1|
|Must be installed by a qualified installer||1||1||1||1||3||3||3||3||3||1||3||1||1||1||1|
|Not dependent on specific site or location for home||1||1||1||2||1||1||1||1||1||1||2||2||2||3||3|
|Must be filled daily||NA||NA||NA||NA||1||1||1||1||NA||NA||NA||NA||NA||NA||NA|
|Manual carrying and loading of fuel to the heater||NA||NA||NA||NA||1||1||1||1||NA||NA||NA||NA||NA||NA||NA|
|Potential to deplete available wood supply if not managed properly||NA||NA||NA||NA||1||1||NA||1||NA||NA||NA||NA||NA||NA||NA|
|Inexpensive fuel/energy source||3||3||2||2||2||2||2||2||2||1||1||1||1||1||1|
|Low fire potential in the home||1||1||2||2||3||3||3||2||1||1||1||1||1||1||1|
|Low carbon monoxide potential in the home||2||2||3||3||3||3||3||2||1||1||1||1||1||1||1|
|Relatively clean fuel when used in the home||1||1||1||1||3||2||2||2||1||1||1||1||1||1||1|
|Green or renewable source of energy||3||3||3||3||2||2||2||2||2||2||1||1||1||1||1|
|No environmental degradation as a result of use||2||2||2||2||3||2||2||3||2||2||1||1||1||1||2|
|Backup system required for cloudy weather, calm days, or low water flows||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1||1||1||1|
|Assess wind or water velocity and/or volume||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1|
|Assess number of days of sun and sun exposure||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1||1||NA||NA|
|Need to be meticulous in monthly maintenance and regular system read out data||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1||1||1|
|Low electrical energy appliances required||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1||1|
|Needs some type of power battery storage and power converters||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||NA||1||1||1|
1U. S. Department of Energy, Science and Technology, Climate Change, http://www.energy.gov/environment/climatechange.htm.
2Taylor, R., “Rising Fuel Costs & Public Safety,” Maine Fire Marshal News, Vol. 1, Issue 10, 2008. http://www.maine.gov/dps/fmo/documents/FMONwsltr10_001.pdf
3Maine Office of State Fire Marshall and Maine Office of Energy Resources, Recommended Standards for the Installation of Woodburning Stoves, 2005. http://www.maine.gov/dps/fmo/documents/2005Woodburningguide.pdf
4U.S. DOE EERE, “Your Home: Active Solar Heating,” Energy Savers. http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12490
5Maine Public Utilities Commission, Standard Offer Disclosure Labels. http://www.maine.gov/mpuc/electricity/standard_offer/disclosure_labels.shtml.
6U.S. DOE EERE, “Your Home: Microhydropower Systems, Energy Savers. http://www.energysavers.gov/your_home/electricity/index.cfm/mytopic=11050
Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
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