HOME RENOVATION - IS GEOTHERMAL AN OPTION?

We've been asked a number of times whether geothermal heating and cooling can work with an existing home.  The answer is YES ... however ... the context of the discussion needs to be adjusted slightly.

 Geothermal drilling of closed loop wells - each tied into the home to supply water to the geo-heat pumps.

Regardless of what technology you are considering for a replacement to an older less efficient heating system, the most important first step is giving attention to the quality of your home's building materials; more specifically INSULATION - which defines the ability of your home to prevent heat loss in the winter and prevent heat gain in the summer. 

Insulation is by far the least expensive way to improve the efficiency of your home.  Once you’ve improved your insulation in the attic, walls, basement, and basement sill, you’ve now significantly reduced the “size” and cost of the mechanical system necessary to heat and cool your home.

The reason this is more significant for geothermal is simple – the size of the geothermal loop is decreased.  While federal tax credits will typically cover the cost of your geothermal loop, by improving the insulation of your home, the initial system costs and the operating costs will be greatly reduced.

And after all, with insulation being the least expensive way to save money – it seems like an easy first step while you make your decision about which heating and cooling system is best. 

Our recommendation is to approach MassSave for an energy audit and do what you can to access the incentives and 0% heat loans available for upgrading.

Net Zero Energy: Technical and Financial Feasibility

Net Zero Energy:  Technical and Economic Feasibility

We’ve been asked a number of times whether Net Zero status is achievable technically using renewable energy products and whether it makes economic sense.  

While there is considerable value to lower carbon emissions for our global environment, our commercial and, to a great extent, residential market choices remain driven by finite resources – i.e. money. Invariably, economics, including initial and recurring costs, ROI, and related payback are primary concerns when making decisions on whether to adopt renewable energy systems are appropriate.

One thing is clear – oil and gas are limited resources and will continue trending upward, and the question of whether renewable-based heating and cooling systems are economically feasible should be asked in conjunction with whether operating costs of traditional fuel-based heating and cooling systems are and will remain economically sustainable …

Our position is that typically no single renewable energy solution will enable Net Zero status in a way that makes sense financially.  Rather, if we approach energy efficiency using renewable more holistically by combining technologies, the Net Zero status or Holy Grail is not only achievable but affordable.

For example combining a highly efficient, well designed, Ground Source Heat Pump (GSHP) system with Solar PV and Solar Thermal can be a very cost effective, predictable energy solution.   Solar PV can provide the electricity required to run the highly efficient GSHP which is used for both heating and cooling.   Solar Thermal can provide nearly 80% of hot water requirements – thereby offloading the heating system, making the size of the heater smaller, with lower energy consumption requirements.

Additionally, there are non-mechanical pieces to this Net Zero puzzle that are equally important.  In fact, looking at the heating and cooling technologies as a complete system is only the first step.  One still needs to integrate not only high-performing heating and cooling technologies but also high-performing building materials – from the perspective of heat loss and heat gain.

Therefore higher quality insulation and R-values in the attic, walls, and basement are important components to achieving Net Zero status.  Higher quality windows, doors, and entry ways, are important contributors to minimizing heat loss in the winter and heat gain in the summer.

By minimizing heat loss and gain, renewable energy systems can be sized smaller, leading to lower initial costs, and lower operating costs.  With smaller heating and cooling demand (or load) on the system, these systems can run more efficiently and outpace traditional combustion systems (oil and gas) on initial and long-term recurring costs.

NET ZERO ENERGY IS TECHNICALLY AND ECONOMICALLY FEASIBLE WITH A MORE HOLISTIC INTEGRATION OF RENEWABLE TECHNOLOGIES AND QUALITY BUILDING MATERIALS

New England Renewable Energy and Mercury Mechanical Services have helped bring on-line another federally funded geothermal system.

The heat pump shown here is just one component of a larger geothermal system. Altough no more visually impressive than an old computer terminal, the entire system produces more than 100 tons (100 x 12,000 BTUs), or 350-400kW of energy.

This federally owned location is strategic to national security. Perhaps analogously, government investment in technologies, such as geothermal, which are critical to long-term national security and economic growth can be illustrated by the US DoD investment in ARPANET starting from the early 1960's.

ARPANET formed the basis for today's internet and became arguably the single most important driver behind decades of public and private investment in computers and communication - what became known as the high-tech industry - the single major contributor to revitalizing our economic growth through the 80's and 90's.

Excellent reading for business and home owners considering geothermal technology ...

Finance 101 for Geothermal Pros ... by HeatSpring Magazine's Chris Williams

http://blog.heatspring.com/finance-101-for-geothermal-pros/

This is a detailed analysis of geothermal versus traditional fuel-based technology system installation costs and cost of ownership.

 

For new construction or complete system replacement, we consistently quote a final cost (after tax credits) that's lower than traditional oil or gas systems with equivalent quality and highest efficiency. 

 

Lessons Learned Selling Community Scale Geothermal

Visit the HeatSpring Learning Institute Blog and learn about the topics and issues we see associated with larger scale geothermal adoption ...

http://blog.heatspring.com/lessons-learned-from-selling-community-scale-geothermal-in-new-england/

We look forward to helping the business and residential community at large implement and benefit from geothermal energy.

Share your thoughts on why geothermal is or is not a good choice for residential or commercial markets.   If you are in a position to make a decision in favor or against, what factors are driving your decision?

Geothermal: How much does it cost?

We install "smart" high-efficiency heating and AC systems that help owners achieve lower more predictable energy costs.

We are strong proponents of both high-efficiency fuel and where and when possible geothermal systems.  Geothermal systems represent low-risk, high-return investments and are simply put - smart.

To gain the benefit of lower energy costs and to eliminate oil dependency, up-front costs are required.  People naturally want to know what they are paying for before making their choice.

Here is a list of typically asked questions received from a home owner in a recent email regarding geothermal:

-----Original Message-----
From: XXXX@hotmail.com [mailto:XXXXXX@hotmail.com]
Sent: Tuesday, May 15, 2012 08:01 PM
To: edward.malloy@nerenewable.com
Subject: Do you do geothermal heating for residences?
I am interested in learning about geothermal heating in a MA residence. How much does it cost to drill the wells? What kind of heating system do you need in the house? What is the pay back time when replacing an oil heating system? P.S. I found your business using the Source for Renewable Energy online marketplace located at http://energy.sourceguides.com 

HERE ARE OUR ANSWERS:
======================

The questions you ask are good ones but to answer them fully and accurately they take some explanation - I suppose that's true with most important items having several variables and considerations.

 

Geothermal is fairly simple from a technology perspective.  It's a water-based heat pump.  It literally extracts heat from water rather than air.  So like a refrigerator - it extracts heat - it does not produce it.  So there are no carbon by-products.  

The fact that water is delivered from the ground (either from a closed loop or open loop system) to the pump at a relatively constant temperature (55degF) allows the geothermal heat pump to operate EXTREMELY efficiently. 

Geothermal systems heat homes somewhat differently than traditional heating systems.  Not only is there no combustion, but the geothermal heat delivered is typically ~120degF.   That's much lower than traditional boilers or furnaces that deliver heat at 180degF.  This higher temperature is why the older systems are much more drying to the indoor air.  For Geothermal heating and cooling, the thermostat is kept fairly constant - less temperature fluctuation = greater efficiency.

 

Regarding geothermal cost.  As efficient as geothermal is compared to gas and oil, it has a higher upfront cost compared to traditional heating and cooling systems.  If you're planning 5 yrs out then Geothermal becomes far more attractive financially.  

For a fair comparison, you need to consider the entire system characteristics.  The geothermal system delivers heating and cooling from one mechanical system (the heat pump).  The system as a whole is made up of 3 primary segments or components - loop, pump/controls, distribution.

 

The final install cost of a geothermal system very much depends on several factors including the insulation quality of the building, the loop type, the mechanical equipment, and the distribution system. 

Regarding insulation quality, if the home or office is well insulated then the geothermal heating and cooling system is smaller (as there is less heat loss and heat gain during winter & summer respectively).  So building characteristics impact geothermal system costs - as they would any high-efficiency heating and cooling system.  

 

The premium for geothermal mechanical (pump/controls) is ~40-50% more compared to new high-efficiency boiler + high efficiency central AC, or approximately $12,000-15,000  (assuming a ~2500-3000sqft home).   While more expensive, geothermal heat pumps are about 4-5x more efficient than the most efficient gas/oil system and 2-3x more efficient than highest efficiency AC system.  

This cost for geothermal mechanicals is typically paid back within a relatively short period given the annual energy savings and the realized tax savings and rebates.  

The other cost associated with geothermal is the loop cost.  That cost is almost always offset by tax credits and state-sponsored rebates.  

 

There are a few different loop types - open and closed.  Each has advantages and disadvantages.  The closed loop is about $2500-3000/12,000 BTUs and the open loop with a single standing column well is about $1500-2000/12,000 BTUs.  

Assume about 700sqft of residential space per 12,000 BTUs.  Sometimes more or less depending on the quality of the insulation. This is a rule of thumb for high-level discussion and never relied on for actual heat load calculations - for this, one must use Manual J.

 

The heating and cooling distribution system can be water-to-water or water-to-air.  With water-to-water, you can use radiant or base-board heat.  For baseboard, you must determine the BTU output capability per foot on an existing system to ensure the older baseboard is sufficient.   

We recommend replacing the old base-board with higher-efficiency slant-fin type base board.  Cooling requires an air handler/blower that circulates conditioned air through a sheet metal or high-velocity duct system.

 

For a water-to-air geothermal pump, which is the simplest system, you can use duct for heating and cooling.  You must do a heating and cooling load (demand) for the home to determine heat loss/gain.  The system size, including the pump and the duct work, are calculated based on the heating and cooling demands. 

 

Back to ROI, again, this greatly depends on several factors but you should assume at least 60-80% heating and cooling energy savings annually.  You can do better than this but it's hard to do worse.  If you are spending $2500-3000/yr then assume at least $2000/yr in energy savings based on today's rates - assuming greater savings with fuel sources increasing - which they always do. 

 

Now, depending on the type of system you choose, you're payback can range between 3-7yrs when you apply tax credits and utility rebates (these rebates and credits are real - don't let anyone tell you differently).   This time frame assumes energy prices remain constant.  

Keep in mind, on payback, obviously, if you choose a high velocity system, the payback is longer since this an expensive distribution system (the cost has nothing to do with Geothermal per se but 30% tax credit does apply to its purchase!!!).  High velocity systems are typically a minimum of 3-4X the cost of traditional duct systems due to materials and labor.   

 

Importantly, you also need to consider fairly that heat pumps have extremely long life-expectancy if maintained correctly (e.g. 35-40yrs) - and we recommend getting life-time warranties on equipment from the manufacturer.  Compared this to 20yrs best case for traditional fuel based systems.

 

Looking at payback is always important.  In doing so the total true value of the system should not be overlooked.  

In addition to energy savings, (as with any system) when a geothermal system is designed and installed correctly, it offers the highest efficiency, it's healthier, lasts longer, brings greater value to the building, is whisper quiet in operation, and has zero carbon contribution (no fuel exhaust), 

Geothermal heating and cooling is simply a smarter choice compared to any other heating/cooling solution.

 

Forgive my passion.  I hope this helps all who consider the choices carefully.

Heating with Geothermal ... "Just A Few Dollars"

A Message (and testimony) from a Geothermal client to a prospective Geothermal client ... 

Cape Cod Geothermal ... this one is a closed loop geothermal system that provides all the necessary heating and cooling to a 2800 sqft home on Cape Cod.  


The owner has had an excellent winter heating season experience with comfortable humidity levels and a very small electrical load which was offset by solar PV panels ...

This particular client combined geothermal with solar PV for a near net zero for all heating, lighting, and appliance energy consumption. 

Please read on ...

-----Original Message-----
From: XXXXX
Sent: Sunday, March 25, 2012 08:54 AM
To: edward.malloy@nerenewable.com, XXXXX@yahoo.com
Subject: Re: Geothermal Experience ...

Dear XXXX,

As per nearly one complete heating season with the use of an all electric geothermal water-to-air system, I am completely satisfied. Although my new home is extremely well insulated and requires a minimal heat load.

I do find that the geothermal pump produces a lower temperature air than the typical oil fired system which makes interior air quality less dry. My humidity levels are so comfortable that I am not even using the built-in humidifier.

My entire electric bill for a 2400 sqft home which includes heat, hot water, lighting, and appliances would have been under $500 for the whole winter. But since I have a solar array on my roof supplying the electricity, my bill was just a few dollars.

The folks at NERES were a pleasure to work with. Their knowledge and experience exceeded my expectations.

If you have any further questions, please feel free to contact me directly at:

XXX-XXX-XXXX

Sincerely,

XXXXXXX