Solar Hot Water for Commercial Properties in Philadelphia & Vicinity


Solar overview:
Commercial Solar Domestic Hot Water:
Solar hot water systems do not generate electricity, but SAVE electricity, or gas, or oil by using solar energy to heat tap water. Solar hot water collectors can operate at up to about 70% efficiency, which is 3 or 4 times the efficieny of PV panels. The general idea is to capture the sun's heat to preheat at least one day's worth of hot water that is stored in a big tank beside the conventional hot water heater. The conventional heater is then fed with preheated water instead of cold water, thereby requiring less conventional fuel. When you take proven solar domestic hot water technology, and then add the economies of scale available on larger commercial installations, the payback period can be as little as 5 to 10 years. From the perspective of increased building value, one can make a case that these systems offer an immediate payback. The owner of our installation at right estimates that for every $1 increase in Net Operating Income, the building value increases $14 (7.1% cap rate). The owner estimates that the reduced gas expenses, led to a corresponding increase in building value that was over twice the cost of the solar hot water system. An additional benefit is that the owner now has less exposure to energy price spikes. A bonus benefit is that the rental manager reports the solar hot water appeals to prospective tenants.

Residential Solar Domestic Hot Water:
These systems may typically take 8 - 15 years to recover their installed cost including the 30% federal tax credit capped at $2,000. A typical residential solar domestic hot water system for a family of 3 or 4 might cost around $7,000 to $9,000 installed (less the $2,000 tax credit) and might generate annual savings in the vicinity of $250 to $500 (gas) to $400 to $800 (electric) per year. In addition, occupants get the satisfaction of taking showers and hot baths with pollution free solar heated water. 
 
Residential Solar Space Heating:
Professionally installed solar space heating systems may take 15 to 30 years or more to recover their installed cost . Solar space heating overlaps into passive solar design (which can have much quicker paybacks). Some do-it-yourself solar hot air installations can have quicker paybacks, but in general, water based solar space heating systems will take about twice as long to pay back than similar size DHW systems. This is because space-heating systems are only generating savings about half the year, while DHW systems are generating savings year round.
 
Photo Voltaics:
PV may require 40 to 50 years to recover the installed cost without subsidies. PV panels generate electricity directly from sunlight. Their efficiency typically is around 15%. (Roof shingle PV systems may be closer to 8% efficient. Some of the newer silicon panels may be as high as about 22% efficient.) An example of a professionally installed residential size 5 KW grid tied PV system without battery backup, could be the one pictured at right, that cost in the ballpark of $34,000 and (in the Philadelphia area) generates about $730 or so worth of electricity over the course of each year (before subsidies or special green energy credits). $34,000 installed cost / $730/year savings = 44 year simple payback. Clean quiet energy generation on site is great, but is expensive. Federal and state subsidies combined with Solar Renewable Energy Credits (SRECs) help make PV much more affordable. Rushforth Solar does not install PV, but there are many area companies that do.
 
 
Pithy Overview of Solar vs. Fossil Fuels:
http://1bog.org/blog/what-if-solar-power-had-fossil-fuel-like-subsidies-infographic/ - to point out how efficient the Solar industry has been with job creation based on the very small amount of subsidies the solar industry has received relative to fossil fuels. (received from Ron Celentano)
 
 
Report Says Clean Energy Gets Fewer Subsidies, Less Investment Than Fossil Fuels:
Los Angeles Times, November 30, 2010
http://latimesblogs.latimes.com/money_co/2010/11/clean-energy-gets-less-subsidies-investment-than-fossil-fuels-says-report.html - Energy from fossil fuel gets 12 times more in subsidies worldwide than sustainable energy, says a new report from the USC Marshall School of Business. That discrepancy, as well as other barriers including high clean-tech start-up costs and low prices for products, keep green investment from booming. (Received from Jan Jarrett, President, PennFuture)
 
 
Alan Rushforth Submitted a White Paper to American Solar Energy Society and Presented it at the ASES Solar Conference in Buffalo, NY
May 14, 2009
Highlights of several commercial drain-back Solar Hot Water installations in 16 to 52 unit Apartment Buildings, all using large non-pressurized EPDM lined tanks.