Research ideas for 1 MW power station using propane generators and solar.

[Millennium]

Hello all,

I hope this is the right subforum to post this thread in; discussion includes generators, solar panels, and large-scale inverters.

I'm looking into the feasibility of building a 1 MW power station and using grid power as backup.
I'd like to get a ballpark figure on costs before spending too much time digging deeper.

Our current power consumption is about 700-800 KW at peak, and our annual electric costs are about $225K.
I've estimated that if capital costs of such a system can be repaid in 10 years, including generator fuel, it's worth the investment.

The location in question is serviced by a poorly run electric company and we've found that the legs are very often out of balance, especially during the summer months, which is destroying the life of our motors and electrical equipment.

My initial thought is to buy 1 MW of solar panels (day) and 1 MW of propane generators (night).
Ideally, we'd have 3x 500 KW generators, 2x running in parallel simultaneously and 1x shut down for service (or as a backup) at any time.

I have not even begun searching for inverters of this size yet, and this is one of my main concerns.
Adding lithium batteries at this time seems prohibitive, unless someone has a good, economical storage alternative to propose.

Any thoughts, input, and ideas are welcome.

Thank you.

 

[Nobodybusiness]

Hello all,

I hope this is the right subforum to post this thread in; discussion includes generators, solar panels, and large-scale inverters.

I'm looking into the feasibility of building a 1 MW power station and using grid power as backup.
I'd like to get a ballpark figure on costs before spending too much time digging deeper.

Our current power consumption is about 700-800 KW at peak, and our annual electric costs are about $225K.
I've estimated that if capital costs of such a system can be repaid in 10 years, including generator fuel, it's worth the investment.

The location in question is serviced by a poorly run electric company and we've found that the legs are very often out of balance, especially during the summer months, which is destroying the life of our motors and electrical equipment.

My initial thought is to buy 1 MW of solar panels (day) and 1 MW of propane generators (night).
Ideally, we'd have 3x 500 KW generators, 2x running in parallel simultaneously and 1x shut down for service (or as a backup) at any time.

I have not even begun searching for inverters of this size yet, and this is one of my main concerns.
Adding lithium batteries at this time seems prohibitive, unless someone has a good, economical storage alternative to propose.

Any thoughts, input, and ideas are welcome.

Thank you.

Beyond my abilities.

 

[AntronX]

Is this some kind of electric co-op you got?

 

[Hedges]

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[ksmithaz1]

I'd peel it into chunks. You don't say what you are doing that uses 1MW of demand, but I'd break the loads into smaller pieces. It would be easier to build out 6 or 7 150KW stations. That is going to pig up a LOT of room. Sounds like you want 3-phase as well, so you will want to put inverters in sets of 3, You really need to defining your average daily usage as well. If you just want to produce 800KW continuous from panels, that's a bloody lot of panels. II'm peaking right now at 13KW with 18KW of panels. A Napikin sez, roughly 12KW from 30 500W panels That would mean you are going to need around 2100 500W panels. Figure these bad boys at 4x7ft. That's a lot of panels, and a lot of real estate. I love solar, but this is my problem with all the greenies wanting the world to go solar, etc and turn off Nuclear,gas, and coal. Lot's of industries use a crap-ton of power, and it rarely makes sense in those scenarios to be 100% on some renewable.

Power in AZ is not expensive, even in the summer at 0.25/kwh, but the sunlight is really good. Generally speaking solar from an inverter is reasonably clean but it's not that great. The minute you put a generator on it, it's gonna get REALLY expensive. Right now I'm paying ~ .07/.10., really a tough sell. I'd look at an enphase type setup that sinmply ties to the grid to reduce peak costs. You could do that at a smaller scale, and anything you produce just reduces the topline.

 

[SamDeleted]

Our current power consumption is about 700-800 KW at peak, and our annual electric costs are about $225K.

What on earth are you running?
That's one big Aircon system ?

 

[ksmithaz1]

There is a solar array at the bakery next to my office. I'll take a pic tomorrow. When I say bakery, I mean the bakery next to the flour mill with the train track in between that bakes bread for the entire west side. Solar is probably a pretty good idea. I think commercial rates are higher, and anything you don't have to pump from the grid is a win for the pocket book. OTOH trying to increase reliability with solar and generators is going to be problematic at best. You just don't have a deep reserve to pull against if your load rises quickly. Some sort of flywheel/gyro arrangement might be interesting, but you get esoteric, and the money gets esoteric right along side. Kind of depends on your load.

If you can get natural gas on the generator side that could make it interesting.

 

[rhino]

This seems beyond what you could do yourself? 1MW of solar would be 2000 500W solar panels to install along with all the mounting and wiring for them. You might want to consider looking for an EPC solar contractor since 1MW would generally be considered "utility scale".

2023 Top Arizona Solar Contractors

This is the 2023 list of Top Solar Contractors completing work in Arizona. The kilowatts listed as being installed in the state reflect only kilowatts installed in Arizona in 2022. Companies listed on this state list could be headquartered in other states, participate in any market (residential...

www.solarpowerworldonline.com

 

[Millennium]

Is this some kind of electric co-op you got?

No, but the potential to evolve into one is there.

 

[Millennium]

What on earth are you running?
That's one big Aircon system ?

Arizona based, so we run AC 8 months a year. ?

 

[Millennium]

I'd peel it into chunks. You don't say what you are doing that uses 1MW of demand, but I'd break the loads into smaller pieces. It would be easier to build out 6 or 7 150KW stations. That is going to pig up a LOT of room. Sounds like you want 3-phase as well, so you will want to put inverters in sets of 3, You really need to defining your average daily usage as well. If you just want to produce 800KW continuous from panels, that's a bloody lot of panels. II'm peaking right now at 13KW with 18KW of panels. A Napikin sez, roughly 12KW from 30 500W panels That would mean you are going to need around 2100 500W panels. Figure these bad boys at 4x7ft. That's a lot of panels, and a lot of real estate. I love solar, but this is my problem with all the greenies wanting the world to go solar, etc and turn off Nuclear,gas, and coal. Lot's of industries use a crap-ton of power, and it rarely makes sense in those scenarios to be 100% on some renewable.

Power in AZ is not expensive, even in the summer at 0.25/kwh, but the sunlight is really good. Generally speaking solar from an inverter is reasonably clean but it's not that great. The minute you put a generator on it, it's gonna get REALLY expensive. Right now I'm paying ~ .07/.10., really a tough sell. I'd look at an enphase type setup that sinmply ties to the grid to reduce peak costs. You could do that at a smaller scale, and anything you produce just reduces the topline.

I thought about doing it piecemeal, but I believe it's more efficient to combine, for this purpose.
We have a campus with many buildings on several hundred acres; real estate is not a problem.

I do appreciate all the input, because one person cannot foresee all the unknowns.
Our power costs were increased 30% nearly overnight by our utility; it's a mess.

 

[Millennium]

This seems beyond what you could do yourself? 1MW of solar would be 2000 500W solar panels to install along with all the mounting and wiring for them. You might want to consider looking for an EPC solar contractor since 1MW would generally be considered "utility scale".

2023 Top Arizona Solar Contractors

This is the 2023 list of Top Solar Contractors completing work in Arizona. The kilowatts listed as being installed in the state reflect only kilowatts installed in Arizona in 2022. Companies listed on this state list could be headquartered in other states, participate in any market (residential...

www.solarpowerworldonline.com

I'm not working alone.
I have a great support staff that would do most of the work.
I'm doing a preliminary feasibility study.
I appreciate the link.?

 

[rhino]

I'm not working alone.
I have a great support staff that would do most of the work.
I'm only considering doing a feasibility study.

Call up SMA for instance then for inverter options for that large of a system. I'm sure they'd be glad to help.

 

[Hedges]

We have a campus with many buildings on several hundred acres; real estate is not a problem.

Is net metering available?
With separate meters on various buildings, you may be able to aggregate bills with production and consumption, so long as all parcels are in contact with each other.
GT PV systems could be on each roof.

I'm less clear on what MW scale AC coupled systems SMA makes. If those battery inverters perform frequency shift, then when grid goes down they should work the same as my Sunny Island. I've got four, 24kW, and they can form a 3-phase network up to 100 kW of battery inverter (without backfeeding grid, but grid could serve as generator). If SMA can make a MW scale grid-backup island for your entire property, you could get net metering plus uninterrupted operation when the grid is down.

The grid is fairly reliable, and maintained by a crew. You want to keep that, only go it alone while the grid is down.

 

[Millennium]

Is net metering available?
With separate meters on various buildings, you may be able to aggregate bills with production and consumption, so long as all parcels are in contact with each other.
GT PV systems could be on each roof.

I'm less clear on what MW scale AC coupled systems SMA makes. If those battery inverters perform frequency shift, then when grid goes down they should work the same as my Sunny Island. I've got four, 24kW, and they can form a 3-phase network up to 100 kW of battery inverter (without backfeeding grid, but grid could serve as generator). If SMA can make a MW scale grid-backup island for your entire property, you could get net metering plus uninterrupted operation when the grid is down.

The grid is fairly reliable, and maintained by a crew. You want to keep that, only go it alone while the grid is down.

No. Our power company is extremely behind the times, and they don't care to catch up.
They are not regulated by any federal agencies; it's a small reservation-run electric utility.

Grid is not reliable, in terms of quality of power. We have severe over and under voltages on various legs.
They won't address a lot of these over/under voltage issues.

We had to run a generator during the day all summer using a generator, because grid voltage would not run our kitchen's walk-in coolers and freezers. It's been a nightmare.

 

[Millennium]

Call up SMA for instance then for inverter options for that large of a system. I'm sure they'd be glad to help.

I will do that.
Appreciate the link.

 

[KauaiMolokai]

You have the resources to do this. Obviously it won’t be DIY or under the radar, but that doesn’t mean you have to get ripped off either. Kauai and doubtless a number of other places have various large solar with battery power stations. You can check the builders of the plants on Kauai by looking up KIUC. They may not be helpful but you can see who built their plants and call these companies. Tesla was one.
Solar contractors will likely be salivating at your project. But if you have the resources to track down equipment and experienced good workers you could avoid spending too much.
One challenge will be remaining ethical - you could learn a lot from contractors without planning to use them. Or you could put it out for bid with a full disclosure that says you’re not paying retail. There are a few good DIY YouTube guys out there who could do this and not rip you off.

 

[Shimmy]

Not to poo poo solar; it is completely feasible (you need about a 100,000 square foot clear roof area and 1-2 parking stalls for the equipment, but it isn't the right solution to your actual problem. You should talk with the utility about either an automatic tap changer (per phase) or a similar type of power conditioner to solve the root problem. Running off propane to cover nights isn't viable, although natural gas could be. (Assuming you run about 500kWh 12 hours a day, 5 days a week, 52 weeks a year the propane cost is likely on the order of $780k/year.)

In the old days I would recommend a Hitech Diesel-rotary UPS for this type of problem, although a static double-conversion UPS or an APC SymmetraMW line-interactive UPS might do the job at a lower cost.

Diurnal energy storage if your overnight loads are over ~2MWh is likely not cost effective on a reasonable timeline. I think 1MWh is readily available though which can buffer your excess solar during the day and save a little at night. The system is likely to cost around $2.5-3 million all-in.

 

[Hedges]

Grid is not reliable, in terms of quality of power. We have severe over and under voltages on various legs.
They won't address a lot of these over/under voltage issues.

Rotary UPS was mentioned.

Simply having a 3-phase motor powering a 3-phase generator should smooth things out quite a bit. Low voltage it simply draws more current. Although imbalanced voltage on legs may be an issue for motors (I only vaguely understand 3-phase power, have seen issues with transformers.)

Double-conversion UPS is another approach. If you build a photovoltaic/battery system, it could be charged by the grid.

Either way, a large system. 1 MW is about 1500 HP worth of motor. 1000A into a 1000V battery.

Easier to deploy on a building by building basis. Besides MW scale, SMA has 6kW 120V Sunny Island, 18 kW to 100 kW 3-phase battery inverter clusters for the US market. European market they have a 75kW battery inverter. Other brands may have 277/480V suitably sized for your buildings. Sol Ark I think has 35kW.

The SMA systems I like do not condition incoming AC; they either connect to pass-through (and charge batteries), or disconnect. A pair of MW scale AC coupled battery inverters back to back could potentially do this for you, with far smaller battery than if you were trying to make it through the night. Then generator is only for power failures.

On the smaller scale, EG4 "Chargeverter" charges battery from AC input, while letting inverter form island grid.

 

[Millennium]

You have the resources to do this. Obviously it won’t be DIY or under the radar, but that doesn’t mean you have to get ripped off either. Kauai and doubtless a number of other places have various large solar with battery power stations. You can check the builders of the plants on Kauai by looking up KIUC. They may not be helpful but you can see who built their plants and call these companies. Tesla was one.
Solar contractors will likely be salivating at your project. But if you have the resources to track down equipment and experienced good workers you could avoid spending too much.
One challenge will be remaining ethical - you could learn a lot from contractors without planning to use them. Or you could put it out for bid with a full disclosure that says you’re not paying retail. There are a few good DIY YouTube guys out there who could do this and not rip you off.

I think the SMA recommendation was a really good one. I've submitted an email to their Engineering and Storage Application departments.

I have a good friend who uses "Tesla" everything, but they're so overpriced, and I hate paying 'brand name' premiums.

I'm not looking for cheap equipment or labor, but definitely want someone who's worth their salt.

I would have no issues paying a savvy technical person, who has the experience and knowledge to avoid possible faults, defects, malfunctions.

Yes, I'd be interested in finding that one DIY genius out there who's looking for such a challenge. Any recommendations?