St. Ignatius Church and the University of San
Franscisco School of Law overlook one of the
Ereklens’ four water-heating systems.
Solar Water Heating
for Apartment Buildings
A San Francisco couple stabilized their utility costs
with four rooftop water-heating arrays.
by LINDA ERKELENS
40 November/December 2010 SOLAR TODA Y solartoday.org
In San Francisco, home to environmen- tal activists of every stripe and numerous renewable energy companies, many build- ing owners have embraced low-carbon technologies. What began as a fad among
environmentally conscious trailblazers has become
a common method of reducing operating costs and
attracting conservation-minded tenants.
My husband, Ron Dion, and I own four San
Francisco apartment buildings, ranging in size
from nine to 21 units. We’ve made it a priority to
reduce our carbon footprint in accordance with
our strong environmental beliefs. We installed
faucet aerators, low-flow toilets and shower-
heads. I instituted a recycling system in coor-
dination with a local nonprofit long before city
ordinances required tenants to recycle waste.
We’re now installing a photovoltaic array on one
of our buildings and evaluating the possibility of
doing three more rooftops.
We recently installed new solar thermal systems on all four buildings, providing domestic
hot water to our tenants. As a backup for rainy
days, we put in high-efficiency boilers burning
natural gas with a 95 percent efficiency rate. The
investment has reduced our utility bills and the
carbon footprint of our residents. Our tenants
now know that the energy used to power their
apartments is mostly renewable.
We had known about the benefits of solar
thermal for years because one of our properties
had a system installed in the early 1980s, feeding
hot water to 21 apartments. When we calculated
the cost and payback of updating that system,
it led us to consider installing solar thermal on
all of our buildings. Then, at a meeting of local
apartment owners, I ran into Chris Chappell
from Sun Water Solar ( sunwatersolar.com), a
Richmond, Calif., firm specializing in thermal
Copyright © 2010 by the American Solar Energy Society Inc. All rights reserved.
Linda Erkelens worked as a computer programmer/
analyst for the University of California – San Francisco
for 25 years. She began investing in rental properties
in the late 1960s and was an early investor in energy-efficiency technologies as a way to save money.