GEOTHERMAL: WHICH BUILDING SIZE IS BEST SUITED, LARGE OR SMALL?

We've been asked if there is a building or home size that's better suited for geothermal applications. The answer is ... not really ... or perhaps better stated ... it shouldn't matter.  If a building, regardless of size, is well constructed and insulated, a well-designed geothermal system is the best choice above all others for long-life and lower operating costs.

Multiple Government Buildings on Large Closed Loop System

Building size is not the concern; rather it's the quality of the building materials, including insulation quality and tightness, and how these items impact the amount of energy necessary to satisfy heating and cooling demands - i.e. impact on the ability to maintain internal room temperatures in the context of heat loss in winter and heat gain in warmer months. 

                                                       

7000sqft Norwell Home with Natatorium (Pool)

 

This more important consideration, building material quality, directly impacts the required size of the geothermal system and therefore the initial and recurring operating costs.  To minimize these costs, the owner should first invest in minimizing heat loss and heat gain.  It can easily be shown how the investment in building materials offers the greater value.

1750sqft Cape Ranch

If it's not clear why, a quick "how it works" overview might be helpful.  With water-based geothermal exchange systems, water provides or transports energy.  More specifically the system operates in one of two modes; either a supply (in case of heating) or removal of energy (in case of cooling).  The provision or extraction of energy will increase or decrease the temperature of surrounding matter.  The higher or lower the temperature of material, the more, or less, energy it contains. 

Community Geothermal - 10 Buildings on Single Closed Loop

In the case of geothermal energy, we are interested in leveraging or accessing the temperature of the earth’s crust – which has in fact captured and stored the sun’s energy. The rotisserie effect of the earth as it orbits the sun has given the earth’s crust a relatively stable and consistent temperature of 50-55 degF in the Northeast.

When we talk about ground source heat pumps (or geothermal heat pumps) we’re typically referring to a technology that utilizes water to conduct heat or energy from the ground into a heat pump which extracts energy and transfers it to the building through the use and conductive properties of water. 

In conclusion, because the geothermal system depends on water to transport the energy, the more energy required – the greater the water flow needed. The more water, the larger the loop field in the case of a “closed loop” system, or the greater the pump size and well water source needed in the case of an “open loop” system. 

Whether a closed or open loop system, the more water needed the more costly the system and the greater the disparity in initial cost between a traditional heating and cooling system versus a geothermal heating and cooling system.  Therefore it’s not the building size … but rather the building material quality that drive suitability of geothermal technology.

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

Thank you and welcome!!

Our mission is to design the highest quality energy systems for commercial and residential applications.
Our goal is simple - reduce your energy costs while optimizing savings, profit, and cost of ownership.
Our objective is to to enable adoption of "smart" energy solutions. 

We invite you to follow us and our community of partners, affiliates, and friends.  We plan to share the realities of available energy and renewable energy solutions; and perhaps why we should or shouldn't adopt certain solutions depending on the nature and objectives of the adopting community or entity.

When we're asked 'what's the best renewable energy solution?' Our answer is "it depends".  Not every renewable solution is right for every situation or circumstance and often times a combination of renewables leads to the best solution for all. 

An important first step before making a decision is to investigate and ask questions.  And be aware, while not always exciting, it's more efficient and less costly to conserve energy than it is to generate (or waste) it! 

Thanks for following!! We look forward to your comments and discussions!