Business Renewable Energy Conversion

[Scott Jesweak]

Hello All -

I'm very interested in proposing a renewable energy proposal to our business mgmt. Our business consumes about 220,000 kw per month. I want to investigate our options for changing where our source comes from.

We have done some internal efficiency savings but I would like to start using better sources that are renewable.

I live in upper Michigan in an area where the average wind is around 12-15 mph.

I'm wondering what recommendations anyone might have to see if wind is the best solution or if another solution might be better.

Our company is in the middle of an industrial district but what is nice about our area is that we live near a farming community that has just put up 3 1.2 gw wind turbines to power from 900-1200 homes.

The project that I propose has to be financially beneficial as well.

[Rob Beckers]

Hi Scott,

Welcome to Green Power Talk!
Are there any RE incentives in your area? If there is anything it will likely make one form of energy production more interesting than another.

Assuming 12 mph annual average wind speed, that is 5.4 m/s. I assume that is at 10 meters height (standard for meteo wind reports)? Plugging that into my generic wind energy production spreadsheet you would be looking at a rotor diameter of around 50 - 55 meters to produce around 200,000 - 240,000 kWh per month, with the rotor at a height of 60 meters (where the wind is just a hair under 7 m/s annual average). Overall efficiency is assumed to be 40%, which for this size turbines is reasonable.

That's a big wind turbine! :amazed:

-RoB-

[Scott Jesweak]

What's the best way to get an average wind speed at certain heights?

One of the things that I saw from my research is that certain large wind turbines kw are calculated at a wind speed of 32 mph or so.

So if I look at our average wind speed which would be around 12-15, this means that we would have to have quite a few small or a couple very large turbines. Based on my calculations for a single turbine for 225kw we would only get roughly 50 kw for our area out of this unit. Spending $200,000 for a unit would be a very long payback since this unit would only generate 1/4 of the power it was rated for.

Not only that but the unit would be very large in the industrial district and then we would have to put up multiple and then try to have them not interfere with each other.

I'm thinking that our power needs will not be best satisfied by wind possibly.

Unless anyone has additional thoughts or routes to go.

[Ethan Brush]

How about PV? Do you have a big flat roof over the facility? Commercial PV often works out to be more cost effective than residential because of the demand charges on commercial accounts. Also the system can be depreciated thru the MACRS program, consult your accountant. Each 100 KW of Pv would give you about 10,000 KWH per month. If I may be honest, renewable energy is rarely done to save money. I think people who want get into RE just because they want to save money are misinformed. I have heard of some PV systems in that have become profitable very quickly but they are in areas with high incentives and large differences in the net metering price paid during solar production hours versus evening and night residential use times. Here in NY, a residential PV system has a payback of 18 to 20 years, assuming no maintenance or repairs during the whole period. Then you have to consider interest not earned on the PV investment, how much longer the system will last after it is payed for, etc. Note that this is coming from a selfish, strictly financial perspective and I wont try to get into the 'real' costs of cheap grid power like the 460+ mountains totaling and area the size of the state of Delaware that are gone from mountaintop removal coal mining and other environmental costs.

[Scott Jesweak]

We are looking at a few different forms of RE at the moment but after contacting our state DSIRE office they said that Michigan doesn't have any commercial RE incentives which would put a big knix on the project to make it affordable. Like as you said, trying to get a company to do such a conversion would have to make financial sense since most companies are in the market to make money.

I have made some contacts with a couple of companies who do solar installations but they said they don't have local offices to Michigan and wouldn't soon because of the lack of incentives.

I really think that until we get a cheaper / watt solution with technology we won't be able to cost justify the project.

[Ethan Brush]

That is too bad about no commercial PV incentives there. Here in NY, there is no commercial net metering, but that is not so big a deal because most commercial accounts will use what they make and dont need the grid as a battery. I think solar thermal is the first option to pursue from the residential standpoint, but for your situation heating is likely small potatoes comapred to the electric bill.