Tag Archives: Renewable

Air Source Heat Pumps in Southeast Alaska

How an air source heat pump works. Photo credit: U.S. Department of Energy.

Air source heat pumps (ASHP) are a heating appliance that act like a refrigerator in reverse.  Where a refrigerator removes heated air from its interior and transfers it to the room, an air source heat pump extracts heat from outside a house, and transfers it to a home’s interior. Using an ASHP in colder climates seems counterintuitive, but the truth is that “cold” outdoor air still contains heat, and an ASHP uses electricity to “step up” that heat to a temperature useful for space heating. Until recently, ASHPs have been used in areas that only experienced mild winters.  However, ongoing advances in technology have resulted in ASHPs that can be installed in colder climates.

Southeast Alaska is a promising candidate for ASHP heating appliances, because it has a milder climate than the rest of the state and access to affordable hydroelectric power. Because ASHPs take some heat from the outdoor air and require less electricity than electric baseboards, they have the potential to reduce heating costs for homeowners who previously heated with electric appliances.

However, there is still uncertainty about the performance of ASHPs in cold climates, and about the barriers to their adoption in Alaska.  CCHRC is planning to explore the opportunity of using ASHPs in Southeast Alaska in a new project: Southeast Alaska ASHP Technology Assessment.  We will conduct a literature review, interview installers, distributers, and ASHP owners, create an inventory of existing ASHPs in Alaska, and model their economic and heating impact.  If you are interested, look for the Technology Assessment on our website in early 2013!

Read CCHRC’s Ground Source Heat Pump assessment here.

What is a ground source heat pump?

A heat pump harvests energy from the ground to use for space heating for your home.

A ground source heat pump (GSHP) is a space heating appliance that uses electricity to convert geothermal heat to a temperature that can be used for indoor heating. They are common in the Lower 48 and quite popular in Europe. There are also several GSHP systems in Alaska, including commercial systems at the Juneau Airport, Weller Elementary School in Fairbanks, and the Alaska SeaLife Center in Seward. Fairbanks has more than 10 residential systems as well.

In the winter, ground source heat pumps work like refrigerators in reverse. Instead of taking heat from the inside of the refrigerator and rejecting it outside, a GSHP gathers heat from the ground, steps it up to a higher temperature using a compressor, and then “rejects” it inside a house. In the summer, some GSHPs can run in reverse mode to provide air conditioning – taking heat from a house and rejecting it to the ground. The main “fuel” for a GSHP is geothermal energy, but it uses electricity to run the compressor. Since the electricity is only acting to boost the geothermal heat (which is free), heat pumps are more efficient than electric heating appliances.

A GSHP consists of 3 parts: the ground loop, the heat pump and the distribution system. The ground loop gathers heat from the ground. It consists of loops of pipes buried in horizontal troughs or vertical boreholes. A pump moves a fluid through the pipes. As the fluid travels, it is warmed up by geothermal heat from the soil and returns to the heat pump with a higher temperature than when it left. Back at the heat pump, the fluid from the ground loop passes its heat to a refrigerant, causing it to evaporate into a gas. The refrigerant fluid then passes through a compressor and its heat can be “stepped up” before it transfers the heat to air or water for the distribution system. Heat pumps can work with a forced air distribution system or a radiant hydronic distribution system, however they generally are not capable of producing hot enough water for baseboard hydronic systems.

Ground source heat pumps are considered a partially renewable technology, because the heat they take from the ground comes from solar and geothermal sources. They are entirely renewable if the electricity they use comes from a renewable source, such as solar or wind. Heat pumps are also very safe to operate, because there is no combustion. They can, however, be expensive to install because you have to excavate land or drill to establish the ground loop. Talk to an installer if you think a GSHP might be right for you.

For more information on ground source heat pumps, see a report by the Cold Climate Housing Research Center and the Alaska Center for Energy and Power: http://cchrc.org/docs/reports/Ground-Source-Heat-Pumps-in-Cold-Climates.pdf. It covers the performance, cost and payback of GSHPs in various regions of Alaska.

Green Gift Wrap Ideas

From eartheasy.com:

Gift wrapping is fun and necessary for many occasions, but there are the environmental costs of resource extraction, manufacture and waste disposal to be considered. You can create attractive gift wrap yourself by reusing paper, fabric or even using the Sunday comics. If you prefer buying gift wrap, look for recycled content gift wrap paper whenever you can find it.

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Tok School burns biomass in big boiler

From The Fairbanks Daily News-Miner, Monday, December 6, 2010:

A new wood energy project in Tok has turned surrounding forests from a fire hazard into renewable fuel. The Tok School lit a new wood chip-fired boiler for the first time several weeks ago.

The 5.5-million-BTU steam boiler produces the school’s heat, saving the school district thousands of dollars in heating fuel and saving forest managers untold costs fighting fires and eliminating waste wood. The school district plans to add a steam turbine generator to the system in May to produce 75 percent of its electricity.

“We’re the first school in the state to be heated entirely by wood,” said project manager and assistant superintendent Scott MacManus, who has been trying to spur wood energy in Tok for 10 years. “As far as I know, we’d be the first public school in the country to produce heat and power from biomass.”

At the school’s new biomass facility, trees and slash are fed into a Rotochopper grinder, processed into chips that resemble wood shavings, spit into a bin and carried by conveyor belt into the boiler, which is

17 feet tall, six feet wide and 12 feet long. Fuel comes from forest thinning projects, scraps and nearby sawmills. The forest around the school has yielded enough biomass for the first year, according to Alaska Division of Forestry spokeswoman Maggie Rogers. Project leaders hope the system will be used as a model of energy independence for other school districts, communities and utilities.

U.S. Needs Critical Boost in Energy Research, Panel Tells Obama

From The New York Times, Wednesday, December 1, 2010:

The United States needs to more than triple its spending on energy research, development and demonstration projects, from about $5 billion now to $16 billion, and should institute a strategic review of national energy policy every four years, an advisory group of scientists and engineers said in a report to President Obama this week.

The United States lags behind other industrialized countries in public support for energy research and risks being overtaken in the development of new energy technologies if added support is not forthcoming, the group warned in the report, by the President’s Council of Advisers on Science and Technology. Security concerns arising from an overreliance on foreign oil and the environmental threat of climate change must also be addressed in a more comprehensive way, the report said.

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Is a Small Wind Energy System Right for You?

From the U.S. Dept. of Energy, Wednesday, November 17, 2010:

When I think of wind technology, an image comes to mind of a towering fleet of turbines. Although I’ve never seen a wind farm up close, I’ve heard from several people that it’s an awe-inspiring sight. I may not have the chance to see a large-scale wind farm anytime soon, but I have had the opportunity to examine a small wind energy system—an alternative source of energy that can fully or partially provide power for the home.

During a recent visit to the U.S Botanic Gardens (USBG) in Washington, D.C., I noticed a vertical wind turbine on display. This single turbine, relatively small in stature, provides up to 2,000 kilowatt hours per year for the USBG. The Garden’s horizontal wind turbine provides an additional 2,500 kW hours per year. Although D.C. is not an ideal windy city, the USBG estimates that these turbines generate enough electricity to light its annual holiday show and power its electric utility vehicle.
In the same way, a small wind energy system can provide a significant amount of clean, renewable energy for your home. Wind turbines work by converting the kinetic energy of wind into electricity. The blades of the wind turbine are aero-dynamically designed to capture the maximum energy from the wind. The wind turns the blades, which spin a shaft connected to a generator that in turn produces electricity. Check out our Energy 101 video series to learn more about wind energy basics.

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New energy: climate change and sustainability shape a new era

From The Christian Science Monitor, Saturday, November 20, 2010:

“Tonight I want to have an unpleasant talk with you,” a somber President Jimmy Carter said gravely into a television camera on an April night in 1977.A series of oil embargoes and OPEC price hikes had hit the nation hard. Gasoline prices had tripled. Auto-dependent Americans had sometimes waited hours in line to buy the gasoline needed to get to work. The president, in an iconic fireside chat — in a beige cardigan — two months earlier had congenially urged Americans to turn thermostats down to 65 degrees F. by day, 55 by night.

But on this night, he ratcheted up his tone: Warning of an imminent “national catastrophe” and scolding Americans for selfish wastefulness, the president declared it time for Americans to curb consumption of oil, which he said had doubled in the 1950s and again in the ’60s — time to end their dependence on imports.

“This difficult effort will be the moral equivalent of war,” he said.

Mr. Carter created the Department of Energy. He called for energy conservation and increased production of coal and solar power. He installed solar panels on the White House.

But his vision — to push America and the world into a new energy era as significant as the shift from wood to coal that fueled the Industrial Revolution — never materialized.

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Nissan Will Sell 500,000 Electric Cars a Year by 2013, Says Chief

From The New York Times,  Tuesday, November 16, 2010:

On the eve of the market debut of the Nissan Leaf electric carCarlos Ghosn, chief executive of the Renault-Nissan alliance, said the only constraint on sales for the next three years will be how many battery packs the factories could churn out.

Deliveries of the Leaf are scheduled to start next month. Mr. Ghosn, speaking to reporters in Washington on Monday afternoon, did not say just how many he expected to sell in the first three years. He said, however, that the Leaf would hit 500,000 units a year in three years. Mass production, he explained, would lower costs enough to make the car a sales success without subsidies sooner than once expected. He said he once thought that number was a million cars a year, but now believed it was from 500,000 to 1 million.

“We’re going to have to put some efforts into selling the car, but the kind of spontaneous demand is going to be driving the sales for the next three years,” Mr. Ghosn said. “There is such a curiosity about the car and attention to the car.”

He predicted that 10 percent of the world car market would be electric vehicles by 2020. “There is no doubt in the minds of anyone in the industry that this is going to be a big factor in the industry,” he said.

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Hydro dam site recommendation to come next week

From The Fairbanks Daily News-Miner, Friday, November 12, 2010:

Analysts in state government who have spent months studying two options for a proposed large-scale hydroelectric dam in Alaska will recommend one next week.

The Alaska Energy Authority officials prefer one site over the other and will name that project as early as Tuesday.

A dam has long been discussed for Southcentral, which is connected to Fairbanks by electric grid. A year-old plan cited Chakachamna Lake, west of Cook Inlet, and the Susitna River as two top spots for the multibillion-dollar proposal.

Karsten Rodvick, a spokesman for the authority, said the agency plans to release its preference in a detailed recommendation next week. It will compare cost estimates, outline detailed construction plans, cite risks expected through permitting processes and list environmental concerns linked to both options.

“The intent of this is not only ultimately to be providing affordable, reliable, sustainable power to the Railbelt,” but also to meet the state’s goal of producing half its power from renewable resources by 2025, he said. He said the agency will post more information about the recommendation on its website following next week’s announcement. It will hold public workshops later this winter

Energy fair offers chance to learn about renewables

From The Tundra Drums, Wednesday, October 27, 2010:

There are plenty of reasons to visit the 2nd YK Delta Regional Alternative Energy and Energy Conservation Fair on Saturday, Oct. 30, at Bethel’s Yupiit Piciryarait Cultural Center.

Vendors greet attendees starting at 10 a.m. and presenters begin at 10:30 and continue until 4 p.m. Admission is free and tables are provided at no charge to vendors thanks to sponsorship by UAF’s Kuskokwim University Campus (KUC), the City of Bethel, Yukon Kuskokwim Health Corporation (YKHC), and Yuut Elitnaurviat, The People’s Learning Center.

Sign up for a ride to visit two working residential wind turbines with Kirk Garoutte of Susitna Energy Systems who will answer your questions about feasibility for your location, cost recuperation, and shipping and installation logistics. The number in Anchorage is 877-485-1100 or 907-222-3992, email info@susitnaenergy.com, web site www.susitnaenergy.com.

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