[Greenbuilding] Daylight harvesting progress

[Nick Pine]

About 10 years ago, I noticed a bunch of lights that were on when the sun
was blasting through lots of clerestory windows above the third floor of
a local college library, so I donated a photocontrol to turn them off.
It was never installed. Since then I've noticed a few more such controls
around campus, controlling outdoor compact fluorescents, but disabled so
the CFs never turn off :-)

About 1 year ago, I donated an Intermatic K4236 photocontrol (2300 VA,
$16.05 as Grainger item 5U790) to a local YMCA with lots of lights near
a dramatic south window, about 40' wide x 20' tall. They are finally
about to install it, and it should save about $500 per year :-) They
even bought another, which should save another $500.

Sunoptics prismatic skylights transmit 40% more light than others, with
no hot spots. They ship the equivalent of 1 MW/week of fluorescents for
installation in Wal-Mart roofs and other places...

In 2003, their president Jerry Blomberg wrote to the CA Energy Commission:

  I know that it is not the Energy Commission's job to improve the working
  conditions of the people of California, but if you required an effective
  skylight to floor area ratio of 2% in all new buildings, it would make
  every building in California a delight to work in. There would be fewer
  divorces, less child abuse, fewer dogs or cats kicked when they are in
  the way. The fact is, daylighted space with an ESFR of 2% reduces stress,
  and stress of any kind weakens our immune systems and increases societies'
  medical costs. California could become known for having wonderful work
  environments in all new buildings...

  To demonstrate the cost effectiveness of daylighting space with skylights,
  I would like to compare the State's photovoltaic subsidy to skylights.
  The State would get six to ten times more energy savings if that same
  subsidy was used to subsidize 100% of the cost of daylighting 
installations
  instead of subsidizing photovoltaic installations at $4.00 per watt. The
  user then has to invest another $4.00 to $5.00 a watt to complete the
  system. One 4 ft. by 8 ft. or 5 ft. by 6 ft. skylight will deliver more
  light than 1 kW of electric lighting during peak demand hours... Over the
  life of a skylight, it replaces electric lighting energy for less than
  $0.015 per kW[h]... we are talking big money here, and by example 
suggesting
  to society that this is where we should be heading. Truth is, if we were
  to rely solely on PV-generated electricity, we would cut our standard of
  living by 50% or more.

  There is no energy shortage on the planet, nor will there ever be
  a shortage. We may run out of some types of energy sources over time,
  but there will be energy available. The problem is to get those energy
  sources into a useful form... The real shortage in the world is money, and
  that must be honored. An adequate supply of least-cost, least-polluting
  energy should be the Commission's primary goal. Daylighting with skylights
  is one example of how this goal can be achieved.

  From the start of our business here at Sunoptics, we set a fantasy goal
  of daylighting enought space to offset the electricity produced by
  a 1,000 megawatt generating plant. Over the last 25 years the acceptance
  of daylighting as a cost-effective energy conservation measure has grown
  to the point where we now ship enough skylights to offset 150 to 200 kW of
  electricity per day, nearly a megawatt a week... The skylights we have
  shipped to date replace electric lighting electricity of 350 to 400
  megawatts during peak demand hours.

But they don't help much if lights are still on. Yesterday I was pleased
to see that most of the lights were off in our local Wal-Mart, except for
those near the walls. Then the sun dimmed, and every 5 seconds or so,
another few hundred feet of fluorescents relit.

Nick