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Re: [Phys-l] Efficiency problem



Answers to Hugh Haskell's questions are below...

I would think that expecting 50% performance factor for a single
large wind turbine is rather optimistic, unless you live in a
particularly windy area (but not so windy that the turbine would have
to be shut down too often because of too string winds).

The Vestas 1, 2, or 3 megawatt turbines have hubs that are 80 meters high. There are four installed in Bowling Green, OH which is 40 miles north of us. They have been operating for several years in the neighborhood of 50%. The wind turbine meteorologist we hired, and the company itself both predicted about 50% in the long run.

Did you consider distributed power generation on campus rather than a
single large (for the size of the project) generation system?
Distributed solar power, meaning installing solar PV panels on any
large rooftop areas and over parking lots, or small wind turbines on
rooftops (vertical axis turbines are often quite suitable for small
installations and are less visually obtrusive or noisy), and then
using the power generated in nearby buildings, where the distribution
system is already in place might have been a more practical
alternative, depending on what storage or additional generation would
be needed for load balancing.

There have been quite a few studies around here that indicate smaller turbines cannot possibly pay for themselves. You have to get them up really high to get them in the steady wind, and also out of turbulence from buildings, trees, etc. If you're going pay the high price of high towers then you need to put something substantial at the top. Anything smaller than about 1 MW does not pay. The 2 MW and 3 MW units seem to be the best cost/benefit ratio for typical Great Lakes states sites.

Virtually all heating (buildings and hot water) is done by natural gas. Even at today's prices for natural gas, it's hard to compete with the economy of natural gas. The best way to win would be to install geothermal electrically powered heat pumps that are powered by large wind turbines. Incidentally, our study showed that geothermal heat pumps in our area (operated from electricity purchased from AEP) would actually increase the university's carbon footprint because AEP electricity in Ohio is 90% coal (10% nuclear) and coal yields twice as much CO2 as natural gas. Thus, if we abandon natural gas and go with geothermal powered by coal-fed generators, we actually become less green.

If you check into the efficiency and economics of small turbines, they just don't pay. As for solar, we are more than 50% overcast in Ohio. Solar can't possibly pay back.

Was the goal of the project saving money, or "getting green"? While
doing both is great, of course, that isn't always possible, so the
university would need to consider how much more they are willing to
pay in order to "green up" the campus.

In today's economic climate we cannot pay much extra for green. We want to be green and save money. If we can't do that then being green has to be reasonably competitive. In most cases it's not. We can't be green if it drives us out of business.

How are the buildings and campus hot water heated? If either is by
electricity, solar thermal panels might have been a good alternative
for either or those tasks, and that would have reduced the electric
load that would have been needed from the wind source(s).

(1) Everything is natural gas. (2) Not enough sun for solar.

Were their any federal or state incentives for the university that
might have reduced the possible pay-back time?

All federal and state incentives are based upon tax breaks. We are nonprofit and don't pay taxes. Only industries paying taxes can take advantage of incentives based upon taxes.

How much effort was put into increasing energy efficiency on campus
that might have also reduced the electrical demand? Building
efficiency is often the low-hanging fruit in projects like this--easy
to do (with some thought and planning) and often much cheaper than
the electricity used to cover the inefficiencies. But such projects,
especially those that depend on large-scale cooperation by the people
impacted need to be as transparent and automatic as possible, and
combined with a PR campaign to get active participation from as many
people as possible.

We have already picked the "low hanging fruit,"

Sometimes, as apparently you found in your study, direct production
of energy is jut not practical, in which case other alternatives can
be sought--making the campus more bicycle-friendly; ramping up a
recycling program; converting the university's motor fleet to
electric or PHEV wherever possible (and using solar PV in the parking
yards to recharge electric vehicles); solar thermal projects, as
mentioned above; converting incandescent lighting to CFL or LED, if
your campus had a central steam heating system, installing a
co-generation system could be a consideration, and steam tunnels can
often be used to do double duty in electric power distribution;
insuring that all new buildings are designed to be as
energy-efficient as possible and incorporate improved energy
efficiency into all existing building renovations; creating a campus
web-site that will display continuously the current and accumulating
energy savings due to campus improvements (such software already
exits and there are several companies that specialize in this type of
installation--check with the folks at AASHE for details)--programs
like this have been effective in getting the campus people involved
in an energy-saving program.

We do not have central heating. Buildings are hot-water heat using multiple sequentially fired 95%-efficient pulsed boilers. As an example, we are heating our 12,000 sq ft science building with a 95% efficient 200,000 BTU/hr pulsed natural-gas boiler. It's hard to beat that. We do have a central computerized energy management computer that runs all our buildings. All campus windows have been upgraded. New buildings have lot's of insulation and older buildings we re-insulated.

I don't know how narrowly focused your study group was or what the
initial charter of the group was, but I hope that it's mandate was a
broad as possible. If all you were allowed to do was look at this
particular wind turbine and how it could be used, then I think you
entered into the project with your hands tied behind your back. A
also don't know whether any of the possible alternatives I've
mentioned would have been practical in your particular situation, but
my list is hardly exhaustive. AASHE is in the business of helping
educational installations "get green," and they can be of great help
in difficult situations.

We started broad, and as the study progressed we discovered that we needed to go big, or not at all, if we wanted to generate electrical energy economically. We hired good consultants and also had knowledgeable people on campus.

Contrary to your conclusion, my impression is that the energy/climate
problem will only be solved if we use the mantra "think globally, act
locally" as at least a major part of our thinking in these matters.
Some things need to be done on a national or global scale, but my
observation of the Washington scene from close up tells me that those
things will only happen when the pressure to do so from below becomes
overwhelming. We have to set the example for the state, federal and
other national agencies to act by showing them how we can do it
locally.

Be careful. Acting locally often makes things worse. A lot of people around here are designing buildings with geothermal heating and are therefore abandoning natural gas. They think they are being green. Far from it. Their electricity comes from American Electric Power which is 90% coal fired, This is out of our hands. Until AEP abandons coal in favor of nuclear or other non-carbon sources, geothermal has a considerably higher carbon footprint than natural gas.

Yes, we can replace all our T12 lights with T8 (which we have done) and we can replace tungsten with CFL and/or LED which we are doing. We are also converting sodium and mercury exterior lighting with LED. It's very expensive and not yet clear whether the payback period will exceed the life of the LED fixtures at today's LED prices.

The bulk of our electrical use during the school year is lighting and computer and other office equipment. Food service uses electricity for refrigeration, but natural gas for most cooking. During the summer our electricity usage increases because of air conditioning.

We have a fairly good recycling program on campus, but it is not as complete as we would like because many things we would like to recycle don't have anybody to take them. For example we cannot recycle all the cardboard pizza boxes delivered to dormitories because food/grease contaminated cardboard is not recyclable (at least not anywhere in NW Ohio). The recycling we are doing costs the university $25,000 more per year than just sending it all to a landfill. It's similar in our village. As a resident I have to pay extra to have a recycling program.

You quickly find out that when you try to act locally that you generally have to pay considerably more, and often can't even do it at any price. Things you can do hardly make a dent in the overall state or national picture. Thinking globally and acting locally generally does little good. Much of what you would like to do is totally out of your control.


Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton University
1 University Drive
Bluffton, OH 45817
419.358.3270
edmiston@bluffton.edu