Renewable Energy

 RENEWABLE ENERGY

Overview:  In most cases, improving efficiency is cheaper and more cost-effective than investing in renewable energy, and should be done first. The reasoning is simple: doing the lower cost items first will give you more money to invest in other energy-savings measures, and the renewable energy systems that you will need will be smaller and less expensive if your losses are reduced first. Once you have reduced your consumption, the following items should be considered.

Solar Hot Water:  A properly-sized solar hot water system (depends on consumption, but generally 2 collectors and a 60-80 gallon storage tank works for an average family) can provide about 75% of your yearly hot water demand. Solar hot water can be retrofitted in most houses, as it requires only a small area (about 60 ft2) of suitable south-facing surface area. The solar systems work automatically to supplement your existing hot water system so you automatically have hot water available regardless of weather conditions. The most common types of solar hot water heaters installed in a freezing climate are drainback and anti-freeze types. The existing Federal and state subsidies for solar hot water are excellent. Generally, prices range from $6000 to $8000 for an average-sized system before subsidies. Exact payback times will depend on the price of the energy you currently use, but a 5-8 year payback time is typical (after subsidies). See the Resources section for information on state and Federal subsidies.

Solar Electricity:  A solar electric system (also called a photovoltaic system) provides electricity directly from the sun. Most systems installed today use net metering, where electricity that is generated from the sun either is used by the homeowner or is directed back into the grid system while turning the electric meter backwards. The “stored” electricity may be retrieved at any time. Grid-independent systems use a substantial number of batteries and are relatively uncommon today. The size of the system (for 100% of your electricity) depends on your yearly electrical consumption, but smaller systems providing half of your consumption can also make sense. Since utilities pay wholesale rates for excess electricity at the end of a year cycle, it makes sense to match your system size to your yearly consumption. With an average electrical consumption of 600 kWh per month, a typical household would need around a 5 or 6 kW system to provide 100% of their electricity. Roughly, a 5 kW system would take up about 500 ft2 of space. While south-facing areas are typically optimal for solar collection, shallow angle west, east and even flat roofs can work for solar electricity, though not quite as well. The full cost of a 5 kW system today is approximately $35,000 (about $7 a watt) without subsidies, but would be less than half of that with Federal and state subsidies. Payback times with subsidies are often 10-12 years, but should be calculated on a case-by-case basis. However, these payback times assume that prices will remain constant, which has never been the case. See the Resources section for subsidy information. You must use a NYSERDA-approved PV installer to be eligible for NYS subsidies.

Sign Up for Renewable Grid Electricity:  For some houses, it will be difficult to locate good solar sites for PV, or the occupant may not want to invest in a solar system. However, it is possible to sign up for different plans for wind and hydro-based electricity with your local utility. This electricity is produced in NYS. The extra cost varies with the plan but it typically a penny or two more per kWh delivered. Contact your utility to find out how to sign up with a renewable energy supplier (ConEd Solutions is one such supplier). O&R will still be your transmission and distribution utility.

Passive Solar Heating:  South-facing surfaces collect a substantial amount of heat energy in the winter when the sun is low in the southern sky. For example, 1 square foot of south window collects about 100,000 Btu (the equivalent of a gallon of oil burned at 70% efficiency) over the heating season. So south-facing windows are good solar collectors. Possible strategies for increasing your solar passive heat gain include: open your curtains and shades on south-facing windows in the winter, add more south facing windows, add a sunspace or solar greenhouse, or add thermosyphoning solar collectors (or fan-run units) in south wall surfaces. All new houses should be oriented properly to maximize southern exposure, with south window area sized appropriately. For passive heating, it is also desirable to block sunlight in the summertime to avoid excess heat gain. This could be as simple as a roof overhang, or a trellis with vines.

Wind:  Small wind systems for households (generally sizes < 10 kW) can be suitable if you have a good wind location. Wind systems can use net metering and there are subsidies available. However, most locations in our area are classified as a 2, possibly 3 (the average wind speed is classified on a scale of 1 to 7, with 7 being the highest), so the wind resource is not exceptional here. There are other obstacles to wind use. These include: permits to build a tower; yearly maintenance, usually provided by wind specialists; and possibly visual, noise, or safety concerns from neighbors. You can find general wind maps for your locality on the web, and information on subsidies from the NYSERDA web site, www.powernaturally.org.

Geothermal:  Using ground or groundwater sources (wells or possibly ponds) for heating and cooling a building with heat pumps (often called geo-exchange) is a possibility. Generally, these work best for new construction (not retrofits to existing heating systems), when both heating and air conditioning are required, and for larger buildings. You should be aware that geo-exchange requires a lot of electrical energy to run the pumps and compressor to circulate the heat to and from the ground, and grid electricity is mainly coal-based. Electrical energy is also the most costly form of energy. If you provide the required electricity from wind or solar, it will require a substantial investment since the geo-exchange system’s electrical load is large. Currently, there are Federal subsidies for geothermal for households, but not NYS subsidies. See www.dsireusa.org.

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