In the previous two blogs of this series of three (Part 1, Part 2), I discussed the concept of passive solar architectural design, the potential for system autonomy, solar electric on-grid power and the way a heat pump works. This blog is about putting these together with a way of controlling their interface to achieve stand-alone heating and cooling systems that are powered by the sun and take energy from the earth or atmosphere, and that working with the patterns of nature approximate perpetual motion. As long as the earth circles the sun this type of system will continuously function within the lifetime of the equipment.
A system that is properly designed will heat and cool a house year around without requiring additional auxiliary heating or cooling. When a ground source heat pump system is coupled with a solar electric photovoltaic system for powering the unit, we create a closed loop operating system that does not need imported, or off site energy to operate. A heat pump can deliver hot or cold water or air to the house by using heat exchange devices; which means it can be used to: provide hot water for radiantly heated floors and domestic hot water, (one of my clients is using a system like this to melt ice off the driveway in winter), cool water or air, or heat a spa or swimming pool. It is best to use a system year around for both heating and cooling to optimize return on the investment. Heat pumps are not the cheapest first cost type of space conditioning systems, but in the long run they are the most cost effective when compared to standard fossil fuel heating or cooling methods.
When a combined photovoltaic powered ground source heat pump installation is activated by a control system that senses the passive solar heat gain to the house, total automated comfort can be achieved. Sophisticated controls can use mean-radiant temperature sensors, differential temperature reading thermostats, and even microprocessors to manage the delivery of heat and cold to different parts of the house. For example in a space heated by a radiant floor if the sun starts shining into the room adding passive solar gain, a mean radiant temperature sensing thermostat will quickly shut off the hydronic delivery to the space to keep it from overheating, automated ceiling or duct fans can be used to further move heated air to remote parts of the house effectively balancing the heat comfort of the entire house.
To see a larger version of this image, click here.
Smart microprocessors with memory capability can anticipate outside sun/temperature affecting the weather skin of the house to allow delivery routines to respond to near future space conditioning needs. These same devices can be set to vary the temperature of various spaces, or zone control, giving custom heating/cooling options to provide better comfort and energy management. For instance the temperature in a bathroom can be reduced at night to save energy when unoccupied, but be programmed to either sense occupancy, or go on at predetermined times such as warming the space in the morning before you rise, or even heating the shower floor and towel bar before you take your normal shower. The limitations are our imaginations.
These developments in technology are available now and will become commonly used in the future as our conventional energy resources become more expensive. Tapping directly into the sun and the earth’s crust, to power and regulate the comfort of buildings, is making good advantage of Mother Earth’s potential. Designing towards a perpetual motion machine is what I consider to be the natural pathway to true sustainability.
This article is published with permission from the University of Washington's Conservation Magazine.
People living near wind farms have complained of headaches, dizziness, and other health problems. Now researchers have found that simply watching videos about these complaints is enough to make others report the same symptoms. (Hat tip: Slate.)
Many residents have fought wind farm development because they worry that sound from the turbines will make them sick. Turbines produce low-frequency sound that isn’t audible to humans, called infrasound. But scientists haven’t found a plausible way that infrasound could cause the symptoms people describe.
The authors tested whether people might be influenced by the widespread reports of wind farm-related health complaints on the Internet. The team told 54 college students that they were being exposed to infrasound for two 10-minute sessions. During one session, the researchers were indeed transmitting infrasound. But the other session was a sham treatment; no sound was actually transmitted.
One group of students watched a video of people describing symptoms that were blamed on wind farms. The other group watched a video of scientists saying that wind turbine infrasound didn’t cause illness. During the infrasound and sham infrasound sessions, the students reported whether they experienced symptoms such as headaches, itchiness, and nausea.
Students who watched the video of health complaints reported more symptoms and more intense symptoms during the exposure sessions than the other group did, the team found. Their symptom scores increased regardless of whether they were being exposed to infrasound or the sham treatment, “confirming that infrasound exposure itself did not contribute to the symptomatic experience,” the authors note in Health Psychology.
The results suggest that Internet reports of wind farm-related health problems could make other people more likely to report the same symptoms. Some people have suggested keeping wind turbines farther away from residents, the team writes, but such efforts “may do little to alleviate health complaints and related opposition to wind farm development.”
Photo by fotolia/Edelweiss
In the previous blog I discussed the concept of passive solar architectural design and the potential for system autonomy. On site power can come from different renewable sources like a solar, wind or fuel cell powered electric generating system that provides annual net-zero energy consumption to completely power the house. In California there are many well established solar electric systems providers and the financial incentives (tax rebates and low interest loans) that help make it feasible to have free electricity. There are on-grid and off-grid solar electric systems; the on-grid essentially uses the commercial power grid as a battery and back-up. The idea of free electric power is exciting and quite feasible in many climate zones, See graphic, below.
(To see a larger version of this image, click here.)
The automated control devices are: differential temperature sensors, microprocessors and timers, systems designed by an energy engineer or air conditioning contractor, to turn on the heat pump system when heating or cooling is needed. These are standard off-the –shelf devices that are readily available, dependable and of modest cost. Differential thermostats monitor temperatures at various locations, say inside and outside air temperatures. When the inside temperature falls low on the comfort scale setting and outside temperature or the ground temperature is warmer, the thermostat will tell the heat pump to turn on and deliver heat where needed. The heat pump can be a ground-source (geo-thermal) or an ambient-outdoor-air-source system to provide the auxiliary heating and cooling required for my passive solar house. The passive solar design itself will vary considerably from microclimate to microclimate, but that is another story to be discussed at another time. The heat pump is a machine that runs on electricity and uses a phase change heat exchange system to provide heating or cooling as seasonally required. By “pumping heat” the exchanger either, extracts heat from, or dumps heat to, a large thermal mass like the ground or the atmosphere. The “ground source” might be a water well(s), buried tubes in the ground (one contractor is placing the heat exchange tubing in the bottom of the septic system leach field) or even a body of water like a pond or lake. The “air source” is generally the air around your house and it is not as steady a temperature as the ground on a day to night (diurnal) basis.
The pumping “medium” is a transfer fluid (gas or liquid) that takes on or releases heat to the earth for the system to provide heat or cooling as needed. When the interior system thermostats and controls call for heat the heat pump extracts heat from the earth’s crust (or air); when cool air is called for it pumps heat from inside the house into the ground(or air) either dumping heat or extracting “coolth”, See graphic, below.
(To see a larger version of this image, click here.)
Ground-source heat pump systems are more effective than outside-air heat pump systems because the earths mass has a dense thermal heat sink in which to store, or extract, thermal energy. Air-source systems are better for cooling, and in cold climates they require another source of heat like gas or electricity to supplement the heat they can extract from the air; they do not work well below 40 degrees F. However air systems are much less expensive to install and they can work well in moderate climates that do not experience widely fluctuating daily or seasonal temperatures. When you combine an independent energy source like solar electric system with a heat pump system you are creating the basis of a perpetual motion machine. To be continued….
The following tip is brought to you by CleanEdison.
Now that you are in the habit of turning the thermostat down (or up) when you’re not around, you have to realize the importance of windows when it comes to efficiency. It’s so easy to open a window a little when you’re not feel at the right temperature. The problem with this is that is drastically reduces the effectiveness of your heating or AC.
Many people don’t know that most HVAC systems don’t produce more or less heating or cooling based on the room temperature – they simply blow air for longer. If you have outdoor air fighting against that, you are going to spend a lot of money without getting very far.
So today, in your school, office or home, make sure that when the heat or cooling is on, the windows are closed. Of course, you can simply decide that the outdoors are a perfect temperature and you want to have the windows wide open, just make sure the AC or heating is off.
The following energy-saving tip is brought to you by CleanEdison.
Tonight when you get home from work or school, call your utility company and ask what incentives they have for you to get an energy audit for your home. Many utilities have been offering free energy audits for years, but very few people have actually taken advantage.
In case you’re unfamiliar, an energy audit is an assessment of your home by a certified energy rater in which they use diagnostic equipment to determine a list of recommendations for how you can improve the efficiency (and comfort) of your home.
If your utility offers free or discounted audits, make an appointment for after April, so you’ll have done most of the easy stuff before he/she gets there.
This article was reposted with permission from Earth Policy Institute.
Freeing America from its dependence on oil from unstable parts of the world is an admirable goal, but many of the proposed solutions — including the push for more home-grown biofuels and for the construction of the new Keystone XL pipeline to transport Canadian tar sands oil to refineries on the U.S. Gulf Coast — are harmful and simply unnecessary. Gasoline use in the United States is falling, and the trends already driving it down are likely to continue into the future, making both the mirage of beneficial biofuels and the construction of a new pipeline to import incredibly dirty oil seem ever more out of touch with reality.
U.S. motor gasoline consumption peaked at 142 billion gallons in 2007. In each year since, American drivers have used less gasoline. In 2012, gas use came in at 134 billion gallons, down 6 percent off the high mark.
Three trends underlie falling U.S. gasoline use: a shrinking car fleet, an overall reduction in driving, and improved fuel efficiency. The number of registered vehicles in the United States rose rather steadily from 1945 to 2008, when it topped out at close to 250 million and then abruptly changed course. As the economic recession hit, new car sales in the United States fell from more than 16 million in 2007 to below 11 million in 2009. For two years, scrappage exceeded new purchases, causing a contraction in the overall size of the fleet. Even with a rebound in sales to nearly 15 million vehicles in 2012, the days of annual sales exceeding 17 million — as seen through the early 2000s — are likely over. (See data.)
The car promised mobility, but in urbanizing communities it instead brought traffic congestion and air pollution. With four out of five Americans now living in urban areas, private vehicle ownership is starting to lose its allure. This is particularly true among younger people, who are readily embracing mass transit and the car-sharing and bike-sharing programs that are popping up in cities around the country. Fewer than half of American teenagers ages 15 to 19 have a driver’s license, a share that has been falling over recent decades as states have tightened restrictions and as socialization patterns have shifted from cruising the streets to cruising the Internet. Retirees also tend to drive less; as the baby boomers retire, more people will be putting away their car keys.
As gasoline prices have risen, private vehicles have traveled fewer miles and public transit ridership has increased. Not only are there fewer vehicles traveling fewer miles on U.S. roads than there were just five years ago, but new cars today can drive farther on a gallon of gasoline. This will soon accelerate: after more than two decades of near-total stagnation, in 2011 the Obama administration increased fuel efficiency standards for cars and light trucks from an average of 27.5 miles per gallon in 2008 to 54.5 miles per gallon by 2025. In addition to the technological changes that can improve the fuel economy of conventional vehicles, new plug-in hybrid electric cars and fully electric vehicles use far less gasoline or even do away with it entirely.
Somewhat counterintuitively, falling gasoline use is at odds with the federal mandate to use more renewable fuel. Under the 2007 Energy Independence and Security Act, the Renewable Fuels Standard (RFS) requires blending increasing volumes of ethanol into the U.S. gasoline supply, regardless of how much gasoline is needed. In 2012, U.S. distilleries produced 13 billion gallons of fuel ethanol, almost entirely from corn. Ethanol accounted for nearly 10 percent of the U.S. gasoline supply. The 2013 requirement for 13.8 billion gallons is likely to go beyond the 10-percent threshold of what can be blended into gasoline and still be used in older vehicles without risking engine damage and voiding warranties.
Furthermore, the RFS requires a growing share of the renewable fuel to come from cellulosic non-food biofuels, yet these have not become economical to produce on a meaningful scale. The increasing production of corn-based ethanol has pitted food use against fuel use, with the unfortunate result of higher food prices. As drought in the U.S. Corn Belt shrank harvests in 2012, corn prices spiked to an all-time high. U.S. corn carryover stocks fell to 6 percent of use in 2012, a historic low. Still, more than 40 percent of the 2012 corn harvest will likely go to fuel cars.
While corn exports from the United States were down in 2012, gasoline exports were up. Higher domestic production and reduced demand allowed the United States to export more oil products than it imported for the second year in a row — after more than six decades of being a net importer. The United States is still a net importer of crude oil, though. Instead of necessarily allowing more gasoline to reach U.S. markets, the proposed Keystone XL pipeline would bring the carbon-intensive Canadian tar sands oil closer to Gulf Coast export terminals for easier access to international markets.
A March 2013 report by the National Research Council describes policies and technologies that would allow the United States to cut its gasoline use 80 percent by 2050. Yet the data they used on the distances being driven only went through 2005, missing the recent drop, and many of the social trends that are starting to drive down car use were not incorporated. These trends are important to consider when envisioning energy and transportation policies for the future. This means rethinking mobility beyond private automobiles. And putting a price on carbon to encourage powering the cars still on the roads with carbon-free wind-sourced electricity can help move the United States beyond ecologically disruptive false solutions that raise food prices and further destabilize the climate.
Photo By Fotolia/lukasvideo
This press release was provided by the U.S. Department of Energy's Energy Efficiency and Renewable Energy News
The Energy Department recognized the East River Electric Power Cooperative of South Dakota and the Golden Valley Electric Association of Alaska in February as the 2012 Wind Cooperatives of the Year.
The 12th annual awards, presented at the National Rural Electric Cooperative Association (NRECA) TechAdvantage 2013 Conference and Expo in New Orleans, honor East River in the generation and transmission cooperative category and Golden Valley for wind energy development by a distribution cooperative. East River and Golden Valley were selected by a panel of experts from the wind industry, utilities, government, national laboratories, and cooperatives.
East River Electric Power Cooperative—Madison, South Dakota
A wholesale electric power supply cooperative serving eastern South Dakota and western Minnesota, East River Electric Power Cooperative is regarded as one of the earliest champions in installing the first utility-scale wind turbines in the Dakotas. In 2009, the co-op created South Dakota Wind Partners LLC (SDWP)—a model for community-based, locally-owned wind development that is fully financed by South Dakota residents. In 2010, SDWP proposed a 10.5 megawatt (MW) addition to the 151 MW Prairie Winds SD1 project and worked with East River to convene investor meetings across the state. This approach helped raise $16 million in just 60 days with investments from more than 600 South Dakotans. The 10.5 MW project has been in operation since 2011, and is a community financing model for clean, domestic wind power that other providers can emulate.
Golden Valley Electric Association—Fairbanks, Alaska
Golden Valley Electric Association is focused on generating 20% of its peak load electricity — power supplied when customer demand is highest — from renewable energy by 2014. As part of this commitment, Golden Valley developed the 25 MW Eva Creek Wind Farm in Ferry, Alaska in 2012. The remote site is located at the end of a 10-mile dirt road, contributing to unique construction challenges. All materials arrived by railroad before being transported by truck along a road that had to be widened and straightened to accommodate the 147-foot-long blades. The Eva Creek Wind Farm project is expected to help the cooperative meet its renewable goals ahead of schedule, reduce dependence on oil, and save Golden Valley members as much as $4 million in annual electricity costs by the end of 2013.
The Energy Department's Office of Energy Efficiency and Renewable Energy accelerates development and facilitates deployment of energy efficiency and renewable energy technologies and market-based solutions that strengthen U.S. energy security, environmental quality, and economic vitality. For more information on DOE's Wind Powering America outreach and stakeholder engagement initiative, visit the Wind Powering America website.
Photo By Fotolia/Radu Razvan