In
April of 2001, it was time - our building needed a new roof. Our
roof was leaking out heat in the winter and letting in heat in the
summer, which wasted precious resources and drove up our energy
costs. After much planning and scores of meetings (decisions are
made democratically at Rainbow -- especially concerning big projects
that affect the entire store), we decided that not only would we
replace the leaky roof with a new high-tech roof, we were going
to embark on three innovative, eco-friendly projects:
Daylight Harvesting
Solar Electric Power ( Photo-Voltaic )
Solar Thermal
Since all of these projects involved working on the roof, Jake Hesse, a member of our Maintenance department, suggested to the Board of Directors and the Membership, that we undertake the projects all at once. Though at first glance the price tag seemed a little steep, it would be well worth the cost because we would be be less reliant on non-renewable sources of energy that are harmful to the environment. Fortunately, we were also able to take advantage of rebates and tax credits from the state and federal governments which reduced the cost. Construction started on our fancy new roof in early summer of 2002. There was a little noise and dust, but store operations continued as normal. Now the new roof and the other projects are nearly complete - and we are excited to show them off!
Daylight Harvesting With
increasing our energy efficiency as our goal, the members of Rainbow
Grocery turned to daylight harvesting. Daylight Harvesting utilizes
available daylight to reduce the amount of electrical light used
in a room. Using a combination of skylights and an automatic control,
electric lights are turned off when there is enough daylight to
sufficiently light the store and turned on when the daylight levels
are too low. Our daylight harvesting system is made up of many skylights.
Each watertight skylight is fitted with a prismatic dome outside
of the building and a diffusing lens inside the building which "spreads
out" the light. The diffusing lens softens the light and cuts down
the heat transference that can affect perishable items in the store.
Solar Electric
In addition to daylight harvesting, another part of the project is the installation of solar electric ( or photovoltaic ) array.
Comprised of tiny cells, the solar electric array absorbs energy from the sun and converts it to electricity without pollution. The cells are laid side by side into larger panels - there are 72 of these panels on the roof at Rainbow.
Although, we cannot rely solely on the photovoltaic panels for electricity, it still provides a cleaner energy source - and we are not paying PG & E for it!.
As solar electric technology progresses, someday we may be able to go "off the grid"...And won't that be cool.
Solar Thermal
with solar electricity, we also use the sun's energy to heat our
water. Large flat boxes with glass covers are installed on the roof
with dark colored copper plates and tubes inside. The copper plates
absorb the sunlight's heat causing it to heat the water that flows
through the tubes. This solar thermal system will provide Rainbow
with half of our hot water for over a year.
In
April of 2001, it was time - our building needed a new roof. Our
roof was leaking out heat in the winter and letting in heat in the
summer, which wasted precious resources and drove up our energy
costs. After much planning and scores of meetings (decisions are
made democratically at Rainbow -- especially concerning big projects
that affect the entire store), we decided that not only would we
replace the leaky roof with a new high-tech roof, we were going
to embark on three innovative, eco-friendly projects: 
With
increasing our energy efficiency as our goal, the members of Rainbow
Grocery turned to daylight harvesting. Daylight Harvesting utilizes
available daylight to reduce the amount of electrical light used
in a room. Using a combination of skylights and an automatic control,
electric lights are turned off when there is enough daylight to
sufficiently light the store and turned on when the daylight levels
are too low. Our daylight harvesting system is made up of many skylights.
Each watertight skylight is fitted with a prismatic dome outside
of the building and a diffusing lens inside the building which "spreads
out" the light. The diffusing lens softens the light and cuts down
the heat transference that can affect perishable items in the store.
with solar electricity, we also use the sun's energy to heat our
water. Large flat boxes with glass covers are installed on the roof
with dark colored copper plates and tubes inside. The copper plates
absorb the sunlight's heat causing it to heat the water that flows
through the tubes. This solar thermal system will provide Rainbow
with half of our hot water for over a year.
