BACKGROUND 2004 renovation of house built in 1850 1979 Heating System: Oil burning furnace with forced air system 1979 Air Conditioning: external heat pump
PROBLEMS 1.No air conditioning in master bedroom 1.Poor heating and air conditioning on second floor because air blown from basement 1.Furnace was 25 years old
INITIAL SOLUTIONS 1.Replace furnace system 2.Replace air handler in basement 3.Add air handler in attic (blow air down) 4.Update ducting system Result Choice of heating system independent of air distribution issues.
CHOOSING A HEATING SYSTEM New oil burning furnace Natural gas furnace: pipeline in front of house Heat pump for heating and air conditioning Tentative Decision Choose oil burning furnace because least costly initial investment and easiest installation.
ALTERNATIVE: GEOTHERMAL Advantages: Replace both heat pump and oil burning furnace Reduce carbon emissions: minus one pound CO2 per hour compared to a conventional system Increase resale value of house System completely in house and in the ground Piping guaranteed for 50 years
COST ANALYSIS ADDITIONAL COSTS Dig three 150 ft wells Pay more in electricity NON-ADDITIONAL COSTS Two new air handlers Improved ducting New system SAVINGS Short run: Not paying for oil or natural gas Long run: Add to resale value
HOW GEOTHERMAL WORKS Ground temperature is consistent 55 degrees Liquid + antifreeze circulates through closed system of pipes Works exactly like a heat pump, except always temperature differential of 15 to 20 degrees: increased efficiency
HOW GEOTHERMAL WORKS SUMMER Heat from air in home transfers to underground loop system and radiates away into cool earth, then cool air circulates back through house WINTER Heat extracted from ground and compressed to higher temperature and used to warm air in home
Air Handler and Heat Pump (1 st floor) Heat Pump (2 nd floor)
Part II: Solar Panel Installation Geothermal Questions?
COST ANALYSIS OF SOLAR PANELS ItemCost Cost (technology + installation)$31,830.40 CEFIA Clean energy Fund Rebate (CT)$7,912.00 Post CEFIA Rebate Value$23,918.40 30% Federal Tax Credit$7,175.52 Final Total Cost$16,742.88
COST ANALYSIS OF SOLAR PANELS Item kWh’s produced annually9,580 Electrical needs met by solar38% Annual electrical savings$1,628.60
PAYBACK AND NPV Item Final Total Cost$16,742.88 Annual Savings$1,628.60 Payback (assume no inflation)10.28 years Barrels of oil per year saved15.39 Add to resale value of house$? Net Present Value over 25 years (includes the original cost) $31,559 + Solar PV System Financial Analysis HandoutSolar PV System Financial Analysis Handout
NUDGES TO ADD SOLAR PANELS CEFIA Clean Energy Fund Rebate (CT) 30% Federal Tax Credit Net Metering
NET METERING If generate more energy than consume by solar panels, then dump energy back into electrical grid and get credit against electric bill
IMPACT OF NET METERING Two electric bills per month: 1.House electric bill 2.Garage electric bill = 1/10 th total electrical cost Result: Install solar panels on garage but connect to House electrical system Why?
IMPACT OF NET METERING SCENARIO 1: HOUSE BILL Produce $180 Consume $100 Return $80 Credit $ —80 Monthly bill $500 Total cost $420 SCENARIO 2: GARAGE BILL Produce $180 Consume $60 Return $120 Credit $ —120 Monthly bill $100 Total cost $0 Waste$ —20 By installing on House ensure never Return more than Monthly bill.
SOLAR PANEL TECHNOLOGY 1.Solar panels generate DC power 2.Connected to Inverter: take DC converts to AC 3.Either use AC power in house or feeds into power grid