industrial use solar power

System

I am opening a mine in a remote part of the Utah Desert (very small operation) I need to run several small (less than 1 HP) and one large (15 HP) electric motor on a regular basis and occasionally an electric furnace. Location is remote from grid. Is there a reasonable solar/battery configuration that is possible. Currently, I am using small generators for power, but as I come more on line I want to convert to a more eco and cost effective system.
Is what I am trying to do reasonable?
If so what kind of configuration would I need?(general terms)
thanks for any and all help

icarus

Re: industrial use solar power

More info would be helpful, for example how much draw is your furnace.

My initial reaction is depending on the number of and average draw of the 1 hp motors, (and how long they have to run per day!) that portion could be solarized in some cost effective way. The 15 hp motor is going to require an very large array/battery configuration (depending how long it has to run). Same with any heating furnace.

Can you fuel the furnace some other way? Propane, fuel oil etc? Electric heat from PV is a very inefficient way of getting heat.

Icarus

BB.

Re: industrial use solar power

Yes, you need to figure out your Watt*Hours or kWatt*hours (kilo-watt-hours).

Assuming you are off grid, solar/battery power is going to cost you north of $1.00 per kWhr (compared to $0.07-$0.30 per kWhr for typical utility power).

Also, off-grid battery powered systems tend to only be around 60% efficient (compared with Grid Tied solar which is ~95% efficient)... Requiring you to about double the number of solar panels ($$$ or $4-$5 per watt just for the panels) for the same amount of power.

You should figure out how much your fuel costs are for generator use (and upkeep) to see how you would like to allocate your resources.

In the end, there are some very worthwhile ways to approach the "energy problem" depending on your needs. If the 1-15 HP motors run only an hour or so per day (like water pump, shaft lifts, etc.), you can build a pretty cost effective way to Solar/Battery power your system and save money vs running a generator 12 hours per day for a real need of 20 seconds of intermittent power.

So, for example, you have lighting needs (CFL/LEDs, and occasional shaft hoist). Power those with batteries/inverters which have very little energy waste for low power application (like lighting) and can manage short surges (lift) very nicely without wasting generator fuel for a generator that runs 98% of the time with 2% load (just to power that occasional 80% load from a hoist).

Next, if you need to pump water from the mine, then use a solar system that only pumps when the sun is shining. Perhaps you would need to size the pump larger (to pump 4-5 hours per day vs a smaller pump running 24/7). Grundfos SQFlex Pumps look very interesting. They can run off of pure solar panels, or, with an automatic switch, can run from 120/240 VAC genset/inverter+battery just fine too.

Then, lastly, for the 15 HP load--run your genset for this. When you need the (example) rock crusher (after you tipped your loads to the input hopper/conveyor), you run the genset at 25-80% capacity (most fuel efficient power band), and can even use the excess power to recharge your battery banks for off-peak loads (sometimes called a hybrid generator system).

Arrange your loads to use the generator efficiently, and use battery/inverters for off peak / low power loads (quiet and fuel efficient).

Use solar PV for special purpose loads (like pumps) and for charging your battery bank (can be shared with generator power).

Lastly, if you need heat--can you use solar hot water/hot air for those applications (cabin heat, hot water, ore drying, etc.)? Generally, solar thermal collector systems will be 1/4 to 1/2 the cost of trying the same thing with solar PV (and even much cheaper than trying to do resistance heating with battery systems).

I will stop here--just some ideas to think over.

-Bill

Also, should add that solar / RE makes great sense for power that is needed 24/7/365 days per year. Generally, does not make near as much sense for occasional power usage (summer weekends, or off season winter weekends when not much sun may be available). The systems are expensive if unused for much of the year. At least, a fuel based generator does not consume any fuel when the site is shutdown.

-BB

nigtomdaw

Re: industrial use solar power

Thats one of the best concise off grid RE usage descriptions I heard for a while and it even covers mining8)......spot on BB.

I copying this for my future use *copy write not with standing*

niel

Re: industrial use solar power

imho it won't work well for all of your needs. as bb said the thermal panels can be of great service to you, but if you are mining at night it won't. you will need either resistance or solar heating methods if this is to be in the mine itself as any fuel-based heat may introduce carbon monoxide and/or co2. also i feel that pvs could allow for a good backup for lights if the genny should run out of gas or fail. this could be done either in conjunction with the genny or use straight up with leds or cfls. 1 hp is over 700w.

System2

Re: industrial use solar power

I've come to respect in a rather short time what BB posts, he is one of the most informative and helpful people on here with an unbiased point of view.

System2

Re: industrial use solar power

Thanks guys, BB in particular for a knowledgeable answer for a novice. I think my best option is to run a solar system for my accomidations and a diesel genset which will power all my needs. If I am going to have to run a genset for one, it is a simple matter to run all electrics on same unit. Costs will be less in the short and long run. I do have access to commericial bio diesel and that will have to do.

Thanks again for your highly informative input
Roger 'Butch' Davies

BB.

Re: industrial use solar power

Roger,

A battery powered system for your home using AC inverters would be a pretty nice setup.

Look at Outback, Xantrex, or a few others mentioned by others here. The inverters are really cool. Basically, one setup would be--Connect the Inverter AC input to your generator, the Inverter output to your home, and the Inverter Battery input to your battery bank.

In this mode, this acts like a giant UPS. When you have AC genset, the inverter passes the power to your home loads and charges your batteries. If the AC fails (or genset is shut down), the inverter automatically switches to battery power and gives you AC output for your home (depending on loads, the inverter can fully shut down and just look for loads when they are switched on--lights, TV, fridge, etc.--to save additional power).

Then you can add solar, wind, hydro power to charge your battery bank with, hopefully, cheaper solar power.

The inverters also have the ability to autostart a generator if the batteries begin to get over discharged.

The inverter/battery/generator/solar system does begin to get a bit dense to explain--but grabbing a manual from one or two of the vendors and reading through them for a few days will clear up most of your questions and help you understand the various options out there for you.

Lastly, for a cost effective solar/battery powered home, knowing how much power you will need (per day, per month, by season, etc.) will be very helpful. A kill-a-watt type meter is a great help and will allow you to size the batteries/solar panels/inverters to your loads.

Once you know how much power you need, send the money on conserving power first. A 100-200 kWhr per month home solar system is a reasonable size/cost. A 500-2,000 kWh per month solar/battery system is closer to a physical/financial nightmare.

-Bill

PS: And thank you very much for the complements.

Could not do this without all of the help from Jim, Niel, and Wind-Sun!