This informative, helpful article, "The energy producing and saving home,"  is written by Ben Cuker, professor of marine and environmental science at Hampton University in Hampton, Va.  His solar-powered home is on tour Oct. 1-2 for the Hampton Roads Solar Tour; admission is free, get map and directions at www.hrsolartour.com.

Background

            Using fossil fuels to power our homes is not a sustainable practice.  Eventually we will exhaust the world’s reserves of coal, petroleum, and natural gas.  But we must act before then, as the consequences of the extraction and use of fossil fuels continue to degrade our environment.  Coal and oil extraction despoil our land, and water ways, natural gas mining poisons aquifers, and the combustion of these fuels fouls our air.  Carbon dioxide is a potent green-house gas that contributes to global climate change, and when it dissolves in the sea it acidifies the oceans. 

What are the alternatives to fossil fuel?

            Electricity produced by gravity-driven water-turning turbines (hydroelectric) is free of harmful emissions and requires no fuel, other than the solar radiation that powers the water-cycle.  Yet it does damage the environment by requiring the damming of wild rivers to form reservoirs. This excludes the fish and other species that are adapted to flowing waters. The resultant flood control reduces the fertility of the river’s flood plain, by cutting off the supply of nutrient rich sediments.

            Electricity from nuclear energy is the most costly to produce, as it requires very expensive facilities.  Nuclear energy plants last only about 50 years and produce tons of radioactive wastes that must be managed for thousands of years. The US still lacks a designated site to store this waste; nobody really wants to live near such a place.  Although the chance of catastrophic failure and release of radioactivity from a nuclear plant is small, the consequences of such an accident are huge and long lasting. Consider the ongoing impact of the Chernobyl disaster in the 1980’s.

            Solar and wind energy provide two excellent sustainable alternatives. Both are intermittent, only working when either the sun shines or the wind blows. So their design application must take this into consideration.  There must be a way to store the energy for later use or to network the home into a system of shared energy. 

            Traditional home design prior to about 1900 assumed that energy production would take place on site.  Judicious placement of windows and porches provided simple passive ways of partially controlling the indoor climate. In climates requiring heating, most houses burned either wood or coal, and also used these fuels for cooking.  First natural gas and then electricity became available for servicing homes in the 19th Century, and these along with heating oil replaced wood and coal.  Beginning in the 1950’s air conditioning became a common feature of more affluent homes, and is considered an essential feature by today’s standards.  The ready availability and cheap price of fossil fuel energy enabled builders to skip the time-tested features of natural climate control and construct designs that relied more heavily on heaters and air conditioners.  So the US is glutted with poorly insulated houses that require massive energy subsidies to keep them habitable during the warm and cold months. 

            It is already feasible to build homes that meet all of the energy demands of their occupants. Such demonstration houses all rely on a combination of super-insulation, passive heating and cooling design elements, and active (solar and or wind) energy generation on site.  While we might think that all houses should be built this way hence forth, local building-codes, don’t reflect such a reality.   Moreover, it is not realistic to think that we are ready to tear-down and replace all of the millions of existing houses. 

            Yet the technology now exists to retrofit the present housing stock for near neutral energy demand.  This requires a combination of demand reduction and onsite sustainable production. 

Reducing Energy Demand

            The simplest way to move toward household sustainability is to reduce the size of the energy subsidy for the house.  Indoor climate control eats up the largest portion of the energy consumed by households.  Measures to decrease this category include; improving insulation in attics, walls and floors, upgrading to low emisitivity windows and doors, sealing cracks and openings that permit air exchange to the outside, switching to compact fluorescent lighting that produces less heat than incandescent bulbs, tuning-up heating and cooling systems for maximum efficiency, turning down the thermostat in winter and up in summer. 

            The second biggest energy demand comes from hot water heaters.   Traditional tank-type electric hot water heaters use more energy than gas units.   First popularized in Europe, tankless or instant hot water heaters fueled by either electricity of natural gas are becoming more common. These use less energy since they only come on when the hot water faucet is opened.  Traditional tanks, even if well insulated, lose most of their heat in storage mode.  Taking shorter showers, washing clothes in cold water and generally avoiding wasting hot water helps conserve energy.

            The next two biggest energy demands come from the refrigerator and clothes dryer.  A modern high efficiency refrigerator uses half the electricity of older units.

Do we really need electric clothes dryers?  Clothing dryers became popular in the 1950’s and 1960’s.  Prior to then, people hung their laundry to dry on lines strung in their back yards, in basements or on porches.  Today many people view laundry on the line as a “low class” act that degrades the appearance of the neighborhood, thus the practice is banned in many communities. Is such an esthetic informed by sustainability?

Lighting is next on the list for energy consumption.  The new compact fluorescent bulbs use about 25% of the electricity required by traditional incandescent versions. Simply remembering to turn off the lights when not in the room also significantly reduces energy demand.  Motion sensors wired to the front porch light will provided security and a welcome to evening visitors, while saving energy when the light is not needed. 

Finally, kill the “energy vampires.”  These are the electronic devices that use small amounts of electricity even when turned off, such as TV’s, computers, stereos, cable boxes, and gaming systems. Use power strips with switches to easily disconnect these energy vampires.

 

Producing Clean Energy on Site

            Electricity - There are two different approaches to using wind and solar energy for the production of energy.   Concentrated production relies on large scale wind farms or solar farms.  Similar to traditional fossil fuel plants, this approach uses a large dedicated footprint for intensive energy production that is then distributed through the grid to our homes.  Few homes offer good locations for wind generation, so such concentrated installations will be the future for electricity from wind.