"Green Machine"

[jheidt2543]

I’d like to raise a discussion topic just to see what the opinions are in the rest of the group regarding “green construction” and wind power in particular.

On page 9, in the October 18, 2004 issue of "Engineering News Record" (ENR) magazine is a small article entitled "Green Machine, Alberici Taps into Wind Power". First of all, this is NOT a knock on Alberici, I’ve heard of the firm, they are highly respected and I have never worked for them or with them.

The article points out that Alberici …”is installing a large wind turbine at its new corporate headquarters that will generate 20% of the building’s annual energy needs.” This sounds great and shows a company’s positive commitment to “green construction”.

The article goes on to say that the building is an industrial conversion of a 110,000 square foot building. The question that came to my mind is, if the wind turbine supplies 20% of the energy needs, then it would take roughly five (5) turbines to provide 100% of the energy requirement of their building (give or take a turbine or two). Take a look at your local industrial park. If it is like the ones in my area, it has buildings varying in size from 25,000 to 300,000 square feet. Wind power would require the sprouting up of tens of dozens of turbine towers, just to supply part of a buildings requirements.

Is wind power really a practical alternative source of power? What would be the reaction to seeing a forest of wind turbines in a new industrial park?

Just wondering!

 

[BobPE]

I have a wind park right outside my office window...There are approximately 40 turbine towers...Our energy company allows customers to "buy" the wind power via a separate billing structure...It all seems good if you are green...I am an engineer, so it makes no sense to me.

Given the turbine efficienceis, inftastructure cost, maintenance, permitting, (i do think they look cool, so I favor them on the horizon), they do not make engineering sense...As such, I can't see them competing with coal and nuclear. I think their true danger is that they divert peoples attention away from the real problem, which in my opinion is providing cost effective energy for all, not just those green people that can afford it at the sacrafice of joe six pack (the common everyday working family).

So, my answer to your two questions would be....no, windpower is a poor attempt at power generation and, yes I enjoy looking at the equipment in a wind farm.

BobPE

 

[StephenA]

There never seems to be enough emphasis on energy conservation.

Good heat insulation in buildings and re-use of heat is much more effective that wind turbines when it is not windy.

StephenA

 

[SlideRuleEra]

jheidt2543 - Wind turbines are cost effective in geographical areas where wind in blowing at fairly steady, predictable speeds most of the time. If this is the case, then the "free" fuel is enough of a benefit to make the windmill a reasonable choice over a long period of time.

So now you have a wind powered generator that is producing electricity more or less around the clock. What to do with that power? The load cycle for a typical office building would vary quite a bit - very little at night or weekends - quite a bit more during working days. The cost effective solution is to size the generator to provide the "base load" for the building - the power required 24 hours per day, everyday. Otherwise you wind up with windmills that have "nothing to do" a large part of the time (the power could be fed into the electric grid, but that's another story).

Twenty percent of an office building's total power requirement sounds like a reasonable estimate for the "base load".

 

[StephenA]

Another way is to store the energy as potential energy. Drive water pumps to pump water up to a reservoir overnight and then drive a water turbine during the day. Not that efficient but the original energy source is free.

Of course you need a handy elevated reservoir of large enough size.

StephenA

 

[cvg]

according to the US Department of Energy, the cost is very competitive with coal and oil fired plants. It seems that connecting them into the grid would be the only way to fully utilize the power. As far as the example cited by jheidt, that turbine was likely sized just for use at that one building, as a larger unit could produce up to several megawatts.

http://www.eere.energy.gov/windandhydro/wind_technologies.html

 

[jheidt2543]

Just a follow-up note. We had a program yesterday at our local Lions Club meeting dealing with wind power. The talk was given by representatives of an organization promoting wind power. They gave the following for the Total Cost/KWhr for various power: Solar $.15; Biomass $.065; Natural Gas $0.055; Coal $0.050 and Wind $0.035. I must have missed the cost of hydro.

Due to the intermitant nature of wind, the maximum expected usage is estimated at 20% of total power required.

A 1500 Kw/hr wind turbine requies about 1/2 acre of land and cost about $1,000,000 installed. It will supply enough power for 600 homes.

Just some more info. to think about.