Tag Archives: Solar

I’ve seen more solar panels around Fairbanks lately. How do they work and what are the different types?

CCHRC has a 12 kW photovoltaic array that is tied to the utility grid.

Solar is a growing resource in Fairbanks, and there are two different types of panels you may be seeing around town: solar photovoltaic, which generate electricity, and solar thermal, which generate heat for space heating or domestic hot water. CCHRC uses both types of panels at the research center. While they both turn sunlight into energy for your home, they have very different applications. Considering your site conditions and heating, plumbing, and electric systems will help determine if one (or both) technologies would work for you.


What’s the difference?
Solar thermal, or solar hot water, collectors absorb heat from the sun and transfer it to water or glycol to provide space heating or domestic hot water.

The two most common types are flat-plate collectors and evacuated tubes. Flat-plate collectors are the oldest and most dominant type of solar thermal. They generally consist of a 4×8-foot glass-encased panel that contains a thin metal sheet, with a dark coating to absorb energy. Beneath the sheet are coils filled with the heat-transfer fluid. Insulation lines the back of the panel to maximize heat transfer to the fluid. Fluid circulates through the tubing, absorbing heat and then transferring it to a storage tank. A typical residential system used to supplement domestic water heating includes two panels.

An evacuated tube collector contains several rows of glass tubes connected to a header pipe. Each tube is a vacuum, which acts like a sealed thermos and eliminates heat loss through convection (due to wind). Because of this, evacuated tube collectors lose less heat to the environment than flat-plate collectors.

A small copper pipe filled with fluid (glycol, water, or some other antifreeze) runs through the center of the glass tube. The fluid heats up, vaporizes, rises into the header pipe, and transfers heat (through a heat exchanger) to another pipe filled with fluid. This fluid carries heat to the storage tank. From here, water can be used for hydronic heating and domestic hot water or converted for other uses.

Solar power
Solar photovoltaic (PV) panels convert sunlight into electricity. They have a silicon sheet that is made up of semiconductors. When light strikes the sheet, part of the energy is transferred to the semiconductors, which knocks electrons loose and allows them to flow freely through connected wires. This flow of electrons is called direct current (or DC). The current then flows into an inverter, which changes it into AC (alternating current), the power used by your appliances. This current can either be used to power appliances (if there is demand), stored in a battery, or returned to the electric grid.

Cold Climate Specifics
Fairbanks is a unique place for solar energy because of the excessive summer sun and the virtual darkness in winter months, which means a few months a year where solar doesn’t contribute much. For example, the 12-kilowatt photovoltaic array at CCHRC produces more than 10,000 kWh from March-September (about 30 percent of the building’s electric demand) but only 1,833 kWh during the rest of the year.

Most households with solar thermal systems use them to offset their primary heating sources. If you want to use solar thermal as a main source, you need some type of seasonal thermal storage system to bridge winter months. PV systems simply offset electricity purchased from the grid in most cases.

With PV, you can produce more power from your panels year-round if you keep them free of snow and change the tilt angle twice a year. The most productive months for CCHRC’s panels are April and May, when they enjoy long daylight hours and also capture reflected solar gain off the snow cover.

Different types of solar thermal panels perform better at different times of the year. For instance, evacuated tube collectors produce more BTUs during the spring and fall shoulder seasons, while flat plate collectors produce more heat during the summer.

Which ones are better to install?
A 1,000 watt PV array will produce about 1,000 kWh a year in the Interior, offsetting $210 in electricity at today’s rates. A two-panel solar thermal system could produce roughly 7 million BTUs a year, offsetting either 54 gallons of oil (saving $215) or 2,050 kWh of electricity (saving $410). In other words, homeowners with electric water heaters stand to save more from solar thermal than those heating with other fuel types.

The actual cost of solar thermal in Interior Alaska (roughly $4-$5 per installed kWh) is lower than solar photovoltaic (approximately $8-$10 per installed kWh). Yet PV panels are still more common in Fairbanks largely because they are easier to install and retrofit, don’t require plumbing, don’t have to be integrated into existing mechanical systems, and have no moving parts (whereas solar thermal systems have fluid and pumps that must be replaced over time).

The actual output and cost of your system will depend on many factors, like the solar exposure of your particular site, the type of heating or hot water system, the type and number of heat exchangers required, and others.

With the cost of conventional energy on the rise, solar is becoming an increasingly attractive long-term investment. Anyone with good solar accessibility may be wise to consider these systems as an option.

Make Your Own Solar-Collector Night Lights

From greenlivingideas.com:

Whether you have a kid, or you’re tired of encountering your darkened hallway walls at midnight, or you simply like the ambience of soft lighting and you don’t want to leave a beacon burning all through the night… an energy-saving night light is a must have.

It’s true that you can get a perky nocturnal hamster and make a hamster-powered night light, but a somewhat simpler project with equally impressive results is a self-crafted Sun Jar…

Invented by Tobias Wong, the Sun Jar is essentially a Mason jar containing a solar cell, a rechargeable battery, and an energy-saving LED lamp.  Placed in a sunlit area by day, the solar cell inside the Sun Jar charges the battery with solar energy and uses that energy at night to power the LED lamp.

Continue reading: Make Your Own Solar-Collector Night Lights

Burning wood? Don’t go green then


By CCHRC Staff

The “Ask a Builder” series is dedicated to answering some of the questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: Does it matter what type of wood I burn in my woodstove?

Most species of local wood are suitable for burning in a stove but do not burn wood that has been treated or painted. Regardless of the species, the best wood to use has been properly seasoned and stored. Wood that is fresh, or “green,” contains higher amounts of moisture, which will bring down a stove’s efficiency and cause excessive particulates and creosote buildup inside a chimney.

On a related point, only burn paper in your stove when starting a fire. Too much paper has the potential to produce a fire that is more than a stove or chimney can handle. Burning coal in a wood stove will have the same effect; so do not burn coal unless the stove is rated for it. Overall, avoid burning large amounts of paper or other combustibles that can significantly raise the stack temperature or cause the stove to burn hotter than it is designed to.

Q: I am thinking of installing solar panels on my home or property. What things do I need to think about before I begin?

There are a number of things to take into consideration when looking into a solar power system. First are the cost of electricity and financial incentives. A solar photovoltaic system has a large upfront cost but will provide savings over many years and will eventually pay itself off. Installing a large solar power system and selling the home a few years later will not provide enough time to pay back the investment. However, even pinning down exact numbers for payback can be a challenge since the cost of fuel and electricity both fluctuate. The federal government also provides tax incentives for solar panels and solar thermal systems.

More information can be found at www.energystar.gov. Golden Valley Electric Association’s SNAP program provides incentives as well.

More information on SNAP is available at www.gvea.com/ energyprograms/snap/.

Another challenge is location. Property on the north side of a hill will not collect as much light as a south-facing exposure. Also look at the amount of direct sunlight on a solar panel throughout the day. Shade from trees and other objects will lower the amount of power you make.

Consider the amount of maintenance that goes into a solar power system. Snow and leaves fall on solar arrays and should be cleaned off.

The amount debris can be limited by tilting panels to 49 degrees in the non-snowy months and 90 degrees in other months, which will also help capture more light from the sun’s low angle.

Contact a professional for further information and tips before getting started with an installation.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org.You can also call the CCHRC at (907) 457-3454.

Get in the know about plugging in your car

By CCHRC Staff home life.


Q: Is there anything I need to be cautious about when plugging in
my automobile?Q: I’ve seen that there are now roof shingles that are solar panels.While a wide range of solar technologies work in Alaska and other cold climates, photovoltaic roof shingles are still too new and untested for cold regions. The basic concept of solar shingles is excellent because the space is usually wasted and basic support structure is already in place. But remember, things perform differently in our extreme climate. If the shingles are glued on, you have to check how that glue performs in cold temperatures. When it comes to solar technology, there are some general rules to be aware of. Anything that applies to solar means you have to have a good exposure to the sun, preferable facing south.Q: What is a heat recovery ventilator and what does it do?

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of

For starters, there are the basics of electrical safety: when you are plugging in anything, you do not want to make direct contact with the circuit because of the risk of electric shock. Besides that, a lot of Fairbanks car fires can be attributed to improperly maintained vehicles. Oil leaks, fuel leaks or other heating elements can be ignited by a small spark. Because winterizing cars in Fairbanks includes installing electrical heating devices, people need to be more cautious about leaks because of the risk of fire.

So if you have leaks, get them checked out and perform any other standard car maintenance.


Could those work in Alaska?


The shingles are going to be covered with snow, so how will that factor into their

East or west might work too, depending on how your roof is built and the pitch of the roof. Consider all the options before choosing a system.


A Heat Recovery Ventilator, or HRV, is designed to bring fresh air into your home. The “tighter” your home is (fewer leaks in insulation, doors and windows), the more essential an HRV is to the safety of the occupants. The other important part of an HRV, heat recovery, means it captures as much of the heat that is leaving the building as possible. You have already heated the air in the house.

To bring fresh air in, you are going to have to expel stale air, but that air has heat in it that you do not want to waste. So the HRV acts as a heat exchanger. As cold fresh air moves in, the warm stale air moves out. When the two air flows pass by each other, the heat from the warm, stale air is transferred to the cold, fresh air through a heat exchanger. These devices will help keep your home warmer in the winter, while saving you energy and money because you do not have to reheat the air coming into your home quite as much.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org. You can also call the CCHRC at (907) 457-3454.

More sunlight equals cleaner Fairbanks air

From The Fairbanks Daily News-Miner, Tuesday, January 19, 2010:

Increasing sunlight has helped improve particulate pollution in Fairbanks, according to borough air quality specialist Jim Conner.

The average particulate pollution level in Fairbanks on Monday was 40 micrograms per cubic meter of air, making the air unhealthy for sensitive groups, Conner said.

Earlier this month, daily averages were reaching nearly 100 micrograms of pollution, which made the air unhealthy for everyone.

What changed?

Conner said weather fronts have been more active and there’s more sunlight. Both help diffuse temperature inversions, when a mass of warm air sits on top of cold air, trapping fine particulate pollution known as PM 2.5, which can embed in the lungs and make people sick.

“When the sun comes up, usually the concentrations (of PM 2.5) drop dramatically,” Conner said. “When the sun goes down, the numbers will go up.”

Click here to read the full story.

Solar-powered Christmas lights – a festive way to go green

From The Christian Science Monitor, Tuesday, December 1, 2009:

There are those who love huge outdoor displays of Christmas lights — life-size reindeer up on the roof and all the trees in the yard covered with glowing bulbs — and those who groan at the sight of a weather-proof extension cord.

If you’re in the latter group, this post isn’t for you. But if you decorate with outdoor lights, you might be interested to find that you can now buy solar-powered decorative outdoor lights.

Click here to read the full story.

In your home, let the sun shine in


By CCHRC Staff

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: Why is it beneficial to have south-facing windows on a home?

Because of the orientation with the sun, south-facing windows bring in both light and heat, which are important for homes in our climate. If you have a lot of north-facing windows, you’re going to lose a lot of heat with not a lot of heat gain.

The amount of heat your home gains from the sun should not be underestimated and sunlight also is good for your mood.

At the same time, some homes can become overheated in months like March, when there is no vegetation to provide shade, and the sun comes directly through your windows. Also, in the summer, the hot sun can overheat your home if your roof does not have enough overhang to shade your windows. Again, trees and other vegetation will help here as well.

Before you build your home, get a sense of where the sunlight falls in both winter and summer. If you are a morning person and you need that morning light to help wake you up, you’ll want to place your windows appropriately. If you like to entertain in the evening summer sun, then put windows in the appropriate place for that. It’s not just about getting light to see and heat your home, think about how light will affect your life in your home.

Q: I want to put a chimney in for a stove, but there are a bunch of things in the way, including a beam. How can I get around that?

It’s always frustrating when you’ve got the perfect place for a stove, but something is in the way. Ideally a chimney should be a straight shot for easy cleaning and proper drafting, but sometimes it just isn’t possible and you’ve got to put an elbow in the pipe. The best place to put an elbow is at the bottom because it allows you to scrub the chimney top to bottom when you clean it and you can still get inside the stove and vacuum out that elbow piece.

Sometimes you can run a stovepipe directly out the side of the house and up the exterior wall. How well this works is case dependent. If there is too much pipe in an uninsulated space, then the pipe can get cold and as a result, some of the smoke will get cold which can cause creosote build up and create a chimney fire hazard. Also, a fire started with a stovepipe that is cold may not draft properly so it may smoke and smolder and even introduce pollutants into your house if it’s not an airtight stove.

Q: What are the advantages of LED lights over those spiral compact fluorescents?

LEDs use less power, have a longer life and are more durable than compact fluorescents. Initially there have been some costs that have kept them from reaching the broad market, but every year brings new innovations in LED technology, bringing the cost down and improving the quality of light they produce. Compact fluorescents contain mercury, so disposing of them is a problem, while LEDs are fairly non-toxic. LEDs also work better than the average bulb in cold temperatures, which is important in our climate.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org. You can also call the CCHRC at (907) 457-3454

Solar incentives may light up US homeowners' pocketbooks

From the New York Times on Wednesday, March 18, 2009:

Solar cells adorn the roofs of many homes and warehouses across Germany, while the bright white blades of wind turbines are a frequent sight against the sky in Spain.

If one day these machines become as common on the plains and rooftops of the United States as they are abroad, it may be because the financing technique that gave Europe an early lead in renewable energy is starting to cross the Atlantic.

Put simply, the idea is to pay homeowners and businesses top dollar for producing green energy.

Click here to read the whole article.

Line drying clothes can save up to 10% of home energy costs

From the Los Angeles Times on Friday, January 6, 2009:

When clothes dryers account for at least 6% of the electricity used by U.S. households, is it any wonder that line-drying is coming back? In places where the practice is banned as an unsightly nuisance to neighbors, right-to-dry activists and blogging eco-moms are forming an alliance. Their cause: to reduce energy consumption and to call upon sunlight rather than bleach to get those whites even whiter.

The movement also includes homeowners pinched by rising electric bills as well as some celebrity converts. Yes, there’s even a blog dedicated to tracking who’s who in L.A. line-drying. (For the curious, it’s blog.linedryit.com/eco_facts/, which lists the likes of “The O.C.” actress Rachel Bilson and singer Olivia Newton-John.)

Click here to read the whole article. Also, be sure to click on the two links in the story for more information.

Obama energy and environment plan

From www.change.gov, retrieved on Thursday, November 20, 2008:

The energy challenges our country faces are severe and have gone unaddressed for far too long. Our addiction to foreign oil doesn’t just undermine our national security and wreak havoc on our environment — it cripples our economy and strains the budgets of working families all across America. Barack Obama and Joe Biden have a comprehensive plan to invest in alternative and renewable energy, end our addiction to foreign oil, address the global climate crisis and create millions of new jobs.

Click here to read the whole page, and find links to other elements of the plan.