By Phil Livingston www.homepower.com
The bulk of our energy comes from coal, oil, and natural gas—exhaustible resources that create pollution when burned. Renewable energy (RE) is non-polluting energy that comes from inexhaustible resources, such as wind, sunshine, and falling water. Using more RE and less nonrenewable energy means less pollution produced. Plus, RE can provide personal and national energy security freeing you from a lifetime of utility bills and reducing the United States´ reliance on imported fuels.
Conservation & Efficiency
Many people get entranced by RE technologies—solar-electric (photovoltaic; PV) modules, and microhydro and wind turbines. But the first focus of anyone wanting to invest in RE should be conservation and efficiency.
Conservation involves changing your energy use behaviors from wasteful, inefficient habits (such as leaving on the lights when you leave a room) to energy-saving ones (turning off the lights every time you leave a room). This is a conscious choice—although you are using the same fixtures, you´re making an effort to minimize your energy consumption.
Efficiency, on the other hand, is reducing energy consumption—without changing your lifestyle—by using efficient appliances. As energy efficiency expert Amory Lovins once said, energy efficiency is a "technical fix." Using the previous examples, the efficiency solution would be to swap out incandescent light bulbs with compact fluorescents (CFs), which only use about a quarter of the energy.
Both conservation and efficiency work hand in hand. Apply the basic principles of conservation and efficiency to all of your energy choices, before looking at harnessing renewable energy. It makes very little sense to put PVs on your roof before you have LED's in your light fixtures.
Conservation and energy efficiency are low-hanging fruit, to be picked before moving forward with solar electricity or hot water systems. By reducing your energy demand, you will greatly reduce the cost of your RE systems when you´re ready to have them installed. Every dollar you spend on efficiency measures will save you roughly $3 to $5 on your renewable energy system costs.
Energy Efficient Appliances
Using efficient appliances can make a world of difference in the amount of energy we consume. Huge advances have been made in a variety of appliances. Here are a few examples:
- Incandescent bulbs produce 95 percent heat and 5 percent light—little has changed since the days of Edison. Welcome to the 21st century-let´s try something new. When you think of compact fluorescent lights, try not to picture the flickering harsh light of years gone by. Modern CFs may provide superior light quality and operational lifetimes over incandescent bulbs, but they contain mercury and are very dangerous when broken. Check out some of the new LED Bulbs on the market—you will be pleasantly surprised. Modern LED Bulbs are far less dangerous for your health.
- In the 1970s, the average refrigerator consumed about 1,500 KWH per year. Today, this number has dropped to about 500 KWH for efficient models. If your refrigerator is more than five years old, replacing it with a more energy efficient unit is a good place to start. Energy Star-qualified refrigerators use 40 percent less energy than conventional models sold in 2001.
- In the past decade, improvements have been made in clothes washer and dryer technologies. New, energy efficient washers agitate on a horizontal axis rather than a vertical one, decreasing the amount of water needed in the washer. Less water used means reduced water-heating bills. The new breed of washers also spins out more water than previous machines, so clothes require less time in the dryer, reducing electricity or gas use. Improvements have been made in dryer technology as well. Dryers now have temperature and moisture sensors, which automatically shut them off when your clothes are dry.
Heating & Cooling
As shown on the pie chart, heating and cooling account for almost 50 percent of the typical American home´s annual energy consumption. Because heating and cooling take such a big bite out of the energy pie, if you´re serious about conservation and efficiency, you´ll start by improving your home´s insulation and reducing air infiltration.
Wall, roof, and floor structures separate the inside of your house from outside, and are referred to as a building´s envelope. How this envelope is designed and constructed is the deciding factor in how good the thermal boundary is between you and the outdoors. Many of us use a thermos to transport liquids because its thermal boundary affords us the luxury of cold lemonade on hot days and hot chocolate on cold days. We want our home to be a thermos of sorts. By designing a building with a tight, well-insulated envelope, you will minimize the energy consumed to keep your home at a comfortable temperature.
Sealing draft-prone areas, the points at which dissimilar building materials converge or the building envelope is penetrated, reduces uncontrolled air infiltration. Combine this with increased insulation and you can reduce the amount of heating, ventilation, and air conditioning needed to sustain a comfortable household temperature throughout the year. This translates directly into greatly reduced heating and cooling costs, and less environmental pollution.
If you´re building a new home, seriously consider a passive solar building design-it´s an inherently superior way to both heat and cool your home. Passive solar houses balance a carefully calculated amount of glazing (windows) with heat absorbing thermal mass (concrete slabs or other masonry material) located on walls and floors in the direct vicinity of the southern exposed windows. Properly sized window overhangs block the high summer sun and prevent the building from overheating, while allowing the low winter sun to enter and warm the space. Another key to passive solar design is to have minimal window area on the north, east, and west sides of the house, to minimize heat loss during cold months and heat gain during the hot months.
Renewable Energy Options
There is no cookie-cutter solution for what type of renewable energy system will be most effective and economical in any given application. Many factors must be balanced to develop a good design, including proper siting, environmental resources, financial incentives, social considerations, and environmental effects. Here is some real-world advice concerning each of the major technologies.
Solar thermal systems include a rather large category of energy collection and distribution devices for pool heating, domestic water heating, and space heating via radiant floor heating or water-to-air heat exchangers. You should consider all these options during the design phase of your project.
Installing a solar domestic hot water (SDHW) system is one of the best investments homeowners can make to reduce their electric or natural gas water heating bills, with typical financial paybacks at less than eight years. Depending on the size of the system you install, your local climate, and your hot water use, SDHW systems can cut your water heating bills by 40 to 80 percent. Systems have been designed for all types of applications. Whether you live in the farthest reaches of Alaska, in cloudy Seattle, or by the beach in Jamaica—an SDHW system can work for you.
The use of residential solar-electric systems began decades ago in rural locations where utility electricity was not available. While the number of off-grid PV systems continues to grow, grid-tied PV systems are an increasingly popular urban and suburban option for generating clean, sustainable electricity. Not to be confused with solar heating (which uses the sun´s heat to warm air or water), PV modules use photons in sunlight to excite electrons and generate electricity. PVs have no moving parts, are virtually indestructible, and typically carry a 25-year warranty.
You´ll face a major choice when planning a grid-tied PV system (and increasingly with wind and microhydro systems)—will you have batteries or not? If your primary motivation is environmental, a batteryless grid-tied system is probably the best choice. Batteryless systems are simple, economical, maintenance free, and highly efficient. If your home experiences frequent or extended utility outages that are an inconvenience to you and your family, then you may want to consider a system with battery backup.
Wind energy can be quite economical if your site has an adequate wind resource. Optimal, consistent wind resources are not located near buildings or down among the trees. Rather, they are found at least 30 feet above all nearby obstructions. Tapping wind energy involves tall towers, which need to be engineered specifically for the turbine you are installing. Wind turbines come in a variety of shapes and sizes, with many different specifications.
If you have a stream running through your property that drops along its course, tapping its energy potential may be economical. With microhydro, as with all renewable energy technologies, you must weigh the economics at each site based on the resources at hand. Opportunities for installing a microhydro system are often few and far between, but if your stream has significant water flow or a large vertical drop (head), you´re in luck. Even streams that only flow seasonally can be good candidates for generating electricity. Unlike PV or wind systems, hydro systems generate electricity continuously, as long as the water is flowing, and will typically be the most cost-effective renewable energy approach.
The Big Picture
Energy efficiency is always the most affordable and environmentally sound place to start when approaching renewable energy. By doing something as simple as swapping out incandescent light bulbs with compact fluorescents, you can decrease the number of PV modules needed to power your lighting by up to 75 percent. This principle applies to all choices you make as you use energy. Focusing on the demand side first will always be your best bet.
Think through your renewable energy choices carefully, evaluating where best to spend your money. Look at your energy appetite and needs, your site, and the resources available to you. As you move towards less and less reliance on nonrenewable energy, you´ll be gaining some independence from the utility companies, reducing your monthly bills, and minimizing the impact our energy use has on the environment
Article From: www.karavans.com
Explore alternative energy options for your home.
One of the major themes of this site will be on how to reduce one's dependence on the "grid" by substituting alternative renewable sources of energy. Some people have even managed to become net energy producers who sell energy back to their local utility company.
Alt Energy Tax Credits
Tax Credits For Energy-Efficiency Home Improvements, Hybrid Vehicles.
A new site operated by the Department of Energy (DOE) and the Alliance to Save Energy will help consumers reduce their federal income taxes in 2006 and 2007 by making their homes more energy efficient and purchasing fuel-efficient vehicles. The site http://ase.org/content/article/detail/2654 covers provisions in the Energy Policy Act of 2005 and is provided as part of the DOE/Alliance Powerful $avings campaign to help consumers reduce their energy bills and the nation lower its overall energy use.
The Internal Revenue Service has not yet issued specific guidance for consumers on how to claim the income tax credits, but in the meantime the web pages offer comprehensive information, based on the new energy law, to help consumers save money on their energy bills and their federal income taxes. The web pages will be updated on a continuing basis as the IRS makes new details available.
Under the new energy law, consumers can save up to $500 in taxes in 2006 and 2007 for specific energy-efficiency upgrades to existing homes. In addition, consumers – and businesses – can save up to $3,400 on energy-efficient hybrid-electric or diesel vehicles purchased.
The Powerful savings http://ase.org/section/_audience/consumers campaign provides tips for lowering energy bills at home and on the road. Consumers also can find a wealth of energy- and money-saving tips in DOE’s free Energy Savers booklet http://www.energysavers.gov/ , which is available in both English and Spanish versions.
Solar Modules for Small Electronics
These devices are designed to recharge laptop computers and small gadgets such cell phones, GPSs, camp lights and other modest-power gear in remote sites
Portable Solar Products
For less money than you think, you can have dependable solar power at your remote cabin or vacation camp. Our kits provide everything you need to produce, regulate and store DC power safely. Real Goods has over 26 years of experience designing solar systems, so we've done the hard work for you.
Windpower: Will it work in your location?
We generally advise that a good, year-round wind turbine site isn't a place that you'd want to live. It takes average wind speeds of 8 to 9 mph and up, to make a really good site. That's honestly more wind than most folks are comfortable living with. But this is where the beauty of hybrid systems comes in. Many, very happily livable sites do produce 8 mph and over during certain times of the year, or when storms are passing through.
Tower height and location also make a big difference. Wind speeds average 50% to 60% higher at 100 feet compared to ground level (see chart in the wind section). Wind systems these days are almost always designed as wind/solar hybrids for year-round reliability.
The only common exceptions are systems designed for utility intertie; they feed excess power back into the utility, and turn the meter backwards.
Wind maps can provide a glimpse into the wind patterns in your region. However, before investing in a wind turbine it's best to take actual measurement at your site.
USA Wind Maps www.windpoweringamerica.gov/wind_maps.asp
First, find out if your location has sufficient wind.
Considering the substantial nature of a windpower turbine it makes sense to first confirm that sufficient wind is present throughout most the year.
NRG WindWatcher. The next generation of wind loggers. Collects and records wind speed and power; calculates average speed and average power density for accurate power predictions; delivers monthly averages from constant 2-second data samples; and saves data at the end of each month. Runs one-year on a single D-cell battery. Includes anemometer with weather boot, stub mast, 100' of sensor wire, ground wire, battery and WindWatcher with surface mounting box. 4.7' square. Designed for indoor or weather-protected mounting.
Will track wind direction and deliver monthly average with optional direction vane. Includes small separate mounting mast and 100' sensor wire.
Affordable wind power turbines for the home and cabin.
Please note that all of these turbines require a mounting system. The higher the turbine is positioned the better it will perform. However, please check with your local county or city government regarding any maximum height restrictions for these towers before purchasing. Towers are sold separately.
But this is where the beauty of hybrid systems comes in. Many, very happily livable sites do produce 8 mph and over during certain times of the year, or when storms are passing through. Tower height and location also make a big difference. Wind speeds average 50% to 60% higher at 100 feet compared to ground level (see chart in the wind section). Wind systems these days are almost always designed as wind/solar hybrids for year-round reliability. The only common exceptions are systems designed for utility inter-tie; they feed excess power back into the utility, and turn the meter backwards.
The third generation of North America's most popular turbine Southwest Windpower has introduced their third generation of the Air turbine series, and things just keep getting better for this simple attractive wind generator. Proven features from previous models include a sleek non-corrosive cast aluminum alloy body, three flexible carbon-reinforced blades, a neodymium permanent magnet alternator, and built-in regulation. What's improved is noise control and charge control. The sophisticated new microprocessor-based speed and charge control delivers better battery charging by optimizing the alternator output at all points of the power curve, it won't overcharge smaller battery packs as the previous generation tended to, and it eliminates the blade "flutter" that was a noise problem at high wind speeds by actually controlling and limiting the blade speed. USA