Larry Lessard on Scaling Geothermal Networks for Maximum Climate Impact

The Green Impact Report Quick take: Larry Lessard reveals why geothermal systems are 400-600% more efficient than fossil fuel alternatives and how network geothermal is revolutionizing district-level sustainability—plus the strategic insight that could reshape your approach to renewable energy priorities. Meet Your Fellow Sustainability Champion Lawrence (Larry) Lessard is an applied scientist with a career encompassing hydrogeology, contaminated site remediation, and geothermal system design and installation.  He is the founder of both Lessard Environmental, Inc. and Achieve Renewable Energy, LLC. He is also a nature and astronomical photographer, third degree blackbelt in Judo, and a Hang Glider Pilot. 🌱Breaking Ground on Better Building In this episode, Larry revolutionizes traditional HVAC approaches: Key Insight #1: Geothermal Efficiency Crushes All Alternatives The Challenge: Natural gas boiler systems max out at 92% efficiency while losing energy up the flue The Solution: Geothermal systems move heat energy instead of creating it, achieving 400-600% efficiency ROI: Equipment lasts twice as long (protected indoors) with dramatically lower lifecycle costs and zero combustion emissions Key Insight #2: Network Geothermal Unlocks District-Scale Impact The Challenge: Individual building systems can't serve properties without underground space or share thermal loads The Solution: Connect multiple buildings to shared ground heat exchangers—cooling-dominant buildings export heat to heating-dominant ones ROI: 100+ year lifespan for ground infrastructure creates generational sustainability investments, like "building a cathedral" Key Insight #3: Target the Biggest Carbon Slice First The Challenge: Many sustainability efforts focus on electricity (only 10-15% of emissions) while ignoring bigger opportunities The Solution: Prioritize building heating/cooling (30%+ of emissions) and transportation (34%) for maximum climate impact ROI: Attacking the largest emission sources delivers the biggest environmental returns and typically the best financial incentives Sustainable Soundbite "If a natural gas boiler system is maybe 92% efficient, a geothermal system, through that same calculation, is 400 to 600% efficient. You get more energy out of the operation of the equipment than you put into it." – Larry Lessard Your Green Building Action Plan Transform your next project with these steps: This Week: Calculate your building's heating vs. cooling loads to determine geothermal feasibility and efficiency potential This Quarter: Explore federal tax credits (30-50% depending on location and domestic content) and local utility rebates for geothermal installations This Year: Evaluate network geothermal opportunities across your building portfolio—identify cooling-dominant buildings that could share heat with heating-dominant ones Connect & Learn More 🌿 Learn about Achieve Renewable Energy: 🔗 Connect with Larry Lessard: 📚 New England Geothermal Professional Association: 📖 Recommended reading: 🎬 Recommended viewing: "Dark Waters" (2019 film) 🗒️ Read the transcript   Want More Green Building Insights? Newsletter coming soon! Green Building Matters, Inc © 2025 | Good Green Fun.