If you are looking for a way to reduce your fossil fuel use while saving money, an air-source heat pump (ASHP) might be a valid option. While this technology has long been popular in warmer southern climates, the colder winter temperatures in the north make it more challenging to extract heat from the freezing outdoor air. Despite this, technological advancements over the past few years have made ASHPs an efficient source of heating in colder climates as well.
ASHPs move heat into a building by circulating a liquid refrigerant between an indoor handling unit and an outdoor radiator. The heat pump heats the liquid by first pressurizing it, pumping it inside from outdoors, and then circulating it through the home’s heating system. The liquid is then depressurized and cooled, after which it travels to the outdoor radiator where the process begins again. ASHPs can also be used to cool buildings through a similar process in which the warm inside air is cooled by the refrigerant, which has been depressurized. The liquid is then sent outside and pressurized, as well as being cooled by the ambient outdoor temperature. The Department of Energy provides a more detailed explanation here of the many different types of ASHPs for those of you who are interested in the more technical aspects of the process.
Energy and Cost Savings
When installed properly, ASHPs can produce between one and a half and three times more heat energy for a home than the electrical energy they use. The Northeast Energy Efficiency Partnerships found that by replacing entire units in the Northeast and Mid-Atlantic regions with air-source heat pumps, the annual savings are approximately 3,000 kWh or $459 when compared to electric resistance heaters and 6,200 kWh or $948 compared to oil systems. When they are used to displace oil, meaning that the oil system remains but is used less frequently, the annual savings is around 3,000kWh or $300. These prices of course depend on the current costs of electricity and oil. The federal government offers a tax credit for ASHPs and a number of states offer rebate programs.
The Right Heat Pump for Your Home
There are a number of options when it comes to choosing the right ASHP for your home, but the most commonly used in retrofits are ductless, mini-split heat pumps because they do not require a ducted heating system. According to the Department of Energy, this type of heat pump also provides a way to heat room additions without extending or installing distribution ductwork. The main advantage to using this type is that one outdoor unit can be connected to as many as four indoor units (meaning it can be used in four different zones or rooms). The typical installed cost ranges from $3,000 to $5,000.
It is also important to choose the right model – one that matches your climate. The traditional way of determining this is by using the EnergyGuide label, which denotes the model’s heating and cooling efficiency. Heating efficiency is determined through the heating season performance factor (HSPF) and cooling efficiency is determined with the seasonal energy efficiency ratio (SEER). Because the HSPF does not include low temperature testing below 17 degrees Fahrenheit, Northeast Energy Efficiency Partnerships developed the cold-climate ASHP specification, which requires manufacturers to report down to 5 degrees Fahrenheit. You should consult these ratings when choosing your ASHP.
Harrisburg, Pa utility provider PPL Electric Utilities has its $40 million smart grid pilot program in a fully operational stage. Currently about 60,000 customers are enjoying the benefits of 21st century technology and a more reliable source of electricity. Just in time for those summer heat waves and storms, too.
Anyone interested in finding out what a smart grid can bring a community or county should take a good look at this latest addition.
With a distribution management system (aka "brain") supplied by GE Energy, the PPL smart grid is constantly monitored and the power flow is analyzed in real time. The "body" of the system comprises over 500 switches, relays, sensors and other devices that can gather information and respond to commands from the control center. A series of wireless towers and fiber optic links make up the "nervous system," bringing communication between system operators and substations in the field.
The whole system benefits users by saving money, improving reliability through quick detection of outages and rerouting of power and providing a foundation for the future integration of wind and solar power.
Well done, PPL and the DOE for the $19 million in funds that helped make the system a reality. Let's hope it serves as a positive example of what this technology can bring to homes across the country.
My sister-in-law in San Diego sent me a message late last week after I tried getting in touch with her:
"Hey! We're in the middle of a rolling black out! The power is out in all of SD!…It's been 100 degrees for three days straight…Killed the power…"
The blackout lasted from Thursday afternoon to Friday morning and affected 1.4 million San Diego Gas & Electric customers.
The cause of the blackout was apparently traced back to a substation outage that caused a transmission line to shut off and trigger a cascade of blackouts that hit San Diego and also spread to parts of Arizona and Mexico.
More ammunition for the Smart Grid advocates, I'd say. One of the most important advantages of the Smart Grid is the elimination of these kinds of cascading blackouts. A Smart Grid would not only be "self-healing" but it could better isolate an outage, limiting the number of customers without power. San Diego's blackout, then, would have been avoided as the outage -- which originated in Yuma -- would have been isolated to Yuma.
Perhaps the building of the Smart Grid could be this country's New New Deal: An investment in an aging infrastructure that would position our country as leaders in energy efficiency. It would create jobs, cut down on greenhouse gases, increase national security. What's not to like?
We are Renovate Your World are unabashed supporters of the Smart Grid. (Which, at times, feels the same as saying we are fans of terra forming and a three-party system.) Fewer and shorter blackouts. Green energy. Smart meters and smart appliances that work for you to save on energy bills. What's not to like?
Two of the bigger challenges facing those charged with making the Smart Grid dream a reality include the distributing of harnessed energy over distances and the storage of renewable energy. While theirs may not be The Answer, the micro-grid designed by McPhy Energy for the University of Nottingham intrigued me. Described as a "mid-term storage of renewable energy," the micro-grid solution stores solar, wind and ground-source heat pump energy as solid hydrogen to cover the homes during peak periods, after sundown and during low- or no-wind stretches of time.
The solution will be used in Nottingham University's Creative Energy Homes project, considered by those involved to be the "first in the world to investigate the use of solid hydrogen as a mid-term solution for energy autonomy on a residential micro-grid scale."
I love the concept. I wonder if this kind of solution is feasible (affordable) on a wider scale. I am curious to know how many homes such a system can support.
Read more about MyCphy's solid hydrogen storage solution here.
Here in Vermont we've had nothing but rain for what seems like the past two months straight. I can count the number of cloudless days we've had since Spring began on one finger. It had me thinking about harnessing the sun with photovoltaics and if such a renewable energy source makes sense for this area.
Naturally, solar panels only work if you have an adequate amount of sun throughout the year. Otherwise you're wasting your money. Just how much sun do you get?
I did a little search to figure out. This is the same kind of research any home will need to do to determine if solar panels are a worthwhile investment.
According to www.city-data.com, my city of Burlington, VT sees cloudless days around 10-15 percent of year, depending on the month, with the fewest cloudless days occurring in November and December. Another site, www.worldfactsandfigures.com, claims that Burlington, VT gets 58 "Sunny" days in the year, which does not include Partly Sunny or Partly Cloudy days. 58? That's a little more than the former site would have me believe. It certainly feels like far less during this current grey stretch.
Incidentally, Philadelphia gets 93 days of uninterrupted sunshine per year, despite what the show would have us think. The sunniest city in the U.S.? Yuma, Arizona, which gets 242. Phoenix is right behind it at 211. The city with the least sun is Cold Bay, Alaska. They get a mere 10 days of sunny days every year. I'm guessing the town doesn't offer rebates for solar panel installation.
With all this said, it needs to be noted that solar panels do work on cloudy days, just not as efficiently. Even on a dark, overcast day a panel can still "soak up" enough diffuse light to be operating at 10 percent capacity. But is that enough over the long-term to make up for the cost? That is the question every home needs to ask before making the investment.
The Winner of the 2010 Earth Awards was recently announced, and it's a product that we may see in commercial and residential construction down the road. Called 'Artificial Photosynthetic Foam,' the winning material was inspired by the foam nest made by the Tungara Frog and is "capable of converting the sun's energy at greater efficiencies than living organisms."
Using this artificial photosynthetic material we will be able to capture carbon and produce energy at much more efficient rates--one can see how these material could have enormous benefits for both commercial and residential application.
Here's a great little article from AltEnergyMag.com that all you city-dwellers should check out. The piece poses the following question: for an urban citizen given a small, open space (whether rooftop, patio, or disused building site), is it more beneficial to plant a small garden or to use the space for harvesting solar electricity?
The article examines the question under three lenses: energy, economic and transport energy.
Lest you dismiss it as op/ed, take a moment to read the first section of the article that compares the "energy balance" of the two options. These folks did their homework. There's real math in there.
Of course, what can't be quantified is the spiritual or emotional value of having a garden over solar power or vice versa. This only the reader can determine. Personally, I'd prefer the garden, as it requires getting the hands dirty and forces upon me some meditative time. Others might prefer the less labor-intensive solar panel.