[Greenbuilding] Daylight harvesting progress

Tue Mar 6 09:53:06 CST 2007

Noticed the same thing at the Chattanooga Trade & Convention Center during
the homeshow weekend-before-last.  During the day when light was flooding
through the skylights, they had the exact same overhead lights burning as
they did during the evening!  What a waste.

Jeannie Babb Taylor
www.SafeCrete.com
706-965-4587

-------------- Original message -------------- 
From: "Nick Pine" <nick at early.com> 

> 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 
> 
> 
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