Geothermal Energy Heating Up

MSNBC has been been reporting on the benefits and growing usage of geothermal heating for your home. We have provided these interesting MSNBC videos for you to view here.

FAQs

Aren’t geothermal systems expensive?
Due in part to the 30% federal tax credit currently available, a new geothermal system may actually be less expensive than a traditional heating and central air conditioning system.  Even if you are comparing a geothermal system price to a traditional heat only system price, the operating savings of the geothermal system will quickly offset the additional investment.  Of course the savings continue to add up long after the system has "paid for itself".  in fact, systems installed in new construction which are included on the mortgage will usually save more money every year than the additional payment on the mortgage, making the cash flow positive from day one!

So how much does a geothermal system cost to install?
Several factors will affect the installation cost of a geothermal system.  The size of the home and the way it was built (insulation values, tightness etc.)  will determine how much heat needs to be collected from the ground and how large your ground heat exchanger needs to be.  The desired heat / ac delivery method will also affect the installation cost.  Radiant flooring is limited to heating only and tends to be more expensive than forced air systems which provide both heating and air conditioning.  Earth coupling methods also vary significantly in price.

Can my hot water baseboard be used with a geothermal system?
The most efficient way of distributing geothermal heat is through radiant in floor tubing, or forced air duct system. A duct system is ideal because it can deliver both heat and air-conditioning. Unfortunately, standard hot water baseboard (HWBB) usually needs to be supplemented (with additional baseboard, fan coil units, or radiators) to provide proper heat output. HWBB, radiant and duct systems can be incorporated in most retrofit applications.

How efficient is a geothermal system?
Efficiency of geothermal heat pumps are measured by coefficient of performance (COP) which range between 3 and 5.  COP-Energy Input/Energy output.  In other words, a COP of 5 means that for every unit of energy used (electricity) 5 unit of heat are delivered to the home.  That's 500% efficient thanks to the free solar heat stored in the ground being delivered to the home.  Based on CMP's basic electric rate ($0.15/Kwh), a heat pump with a COP of 4 will deliver heat for the equivalent of about $1.20 per gallon or oil.

Are there any incentives to installing a geothermal system?
Along with low operating cost, low maintenance cost, and low Co2 emissions, there are tax credits, low interest loans, and reduced utility rates available to geothermal system owners. The stimulus bill includes a 30% tax credit for homeowners and 10% for businesses. The Maine legislature recently passed an act to provide a rebate of up to $1,250 for clean energy geothermal heating units (Sec. 1.35-A MRSA 3211-D). The Maine State Housing Authority (MSHA) provides low interest (3.95%) loans thru the Home Energy Loan Program (HELP) with generous income limits for up to $30,000. Bangor Hydro Electric offers a 17% reduction in their delivery rate during the heating season (Oct.1-May1) to home owners heating geothermally

Do I need a supplemental heat source?
No. A properly sized geothermal system can heat any house or business regardless of outdoor temperature. Unlike air-source heat pumps, ground source heat pumps do not rely on air temperature to produce heat and air conditioning. Ground source heat pumps rely on the relatively constant temperature of the earth as a heat source, or heat sink. However some systems do have supplemental heating sources built-in, and the heat pumps are downsized slightly so they run at peak efficiency for more hours of the year. The supplemental heat (often electric) comes on; only on the coldest few days of the year.

What about domestic hot water?
Geothermal heat pumps often use what is called a 'desuperheater' to capture excess heat from the refridgeration circuit in order to make hot water.  This is a domestic hot water assist option that is used to supplement a traditional primary hot water system.  When air conditioning, heat that is removed from the home is used to produce free hot water, during heating season, the water is heated with the same efficiency as the heat pump.

Do I have to pay some one to clean my heat pump every year?
No, unlike a typical oil furnace, ground source heat pumps do not require regular maintenance other than changing filters associated with a duct system.

How will a geothermal heating system affect the value of my home?
In today’s competitive housing market, any increase in efficiency will greatly increase a homes value. In fact, according to the National Association of Realtors, a $1 reduction in utility bills equates to a $20 increase in home value (www.realtor.org ). Geothermal systems often save homeowners $2,000-$5,000 per year. Geothermal systems also have the benefit of providing air conditioning which also greatly improves a home’s value.

What size system will my home need?
Identifying how much heat a home will need is the most important part of any heating system design.  ELCO performs "Manual J" heat load calculations for every system.  These calculations account for climate, home size, insulation values, door and window quality and other factors to determine exactly how much heat a home will require on the coldest day of the year.  With this information, we can specify the right size heat pump, and design the right size earth coupling system.  A 2,000 square foot home can be anywhere from 3 tons (36,000 btu/hr)up to 6 tons (72,000 btu/hr) due to variations in construction and home design.

Can I visit a home with a  geothermal system?
Yes, we would be happy to show you an existing installation at your convenience.

What type of geothermal system is best?
The answer to this question depends on your building lot.  Each type of system has unique advantages and disadvantages.  For instance, closed loop systems tend to be more costly to install than open loop options.  However, closed loop systems generally have a lower "lifetime" cost due to reduced maintenance issues.  Lot size, soil conditions, depth to ledge and assets such as existing water wells or private ponds will dictate which type of system is most cost effective for you.  ELCO has installed open loops, standing column wells, horizontal loops, and vetical closed loops and can help you decide which is most appropriate in your specific circumstances.

I thought horizontal closed loops won't work in Maine?
A properly designed and installed horizontal loop works just as well as a vertical closed loop...even in Maine.  All closed loop systems are designed to have a minimum entering water temperature with a certain amount of pipe.  The footage of pipe a system requires will depend on the depth of the pipe and soil conditions among other factors.  Even though a horizontal loop system may require significantly more pipe in the ground, it can generally be installed for less money than a vertical system assuming depth to ledge is not a factor.  We would be happy to provide references from one of our satisfied customers.

I think I want a horizontal closed loop system, but I don't know if I have ledge.
No problem, ELCO owns an auger truck (typically used for telephone pole installation) which can quickly and easily test for ledge depth.

Where can I learn more?
You can always call ELCO or fill out the "contact us" form on the website to have your questions answered.  You may also check out www.climatemaster.com (Climate Master heat pump manufacturer) or www.igshpa.okstate.edu (International Ground Source Heat Pump Association) for additonal information.