How far can you locate solar generation from the end use place?
System Posts: 2,511 admin
I would like to spread the cost of a solar installation over two residences - both are conservative users of power. As the crow flies, the houses are 633 feet apart and connecting by wire would be more distance as the terrain does not lend itselt to a straight line. But the basic question is, can you ship solar power this far from the source? Initially, my plan is to capture the sun at the sunniest location which would make the distance even greater. Depending on the answers I get, perhaps I can rethink and figure out how to locate the collector panels somewhere between the two houses. Thanks in advance.
0 · Share on Twitter
this is an interesting scenario as most won't be able to share in such a way something as big in nature as solar would be without drawing up a contract to insure the interests of all parties are agreed upon and followed. now if all is good between the 2 parties involved i would have to know if this is to be a battery backed system or straight grid tie system. with the battery system this allows for backup to the grid or no grid at all, but the other (straight grid tie without battery backup) has no batteries and just runs the electric meter backwards. in any case i'd recommend sending the power after it has been inverted to 110vac or even 220vac with the kind of distance involved to the next house. you still have to have wires, but battery voltages being sent that kind of distance would lose too much power via voltage drops even if using 48vdc. with higher currents and distances involved you experience more of a voltage drop and higher power losses and you will in all probability need some heavy wires. you may have less of a loss and smaller expenses keeping the pvs on the less productive property to provide for that less productive property rather than putting them over at the better situated property and sending the power that distance to the poorer one. you will have to determine which is better as none of us could do that for you by descriptions. even compromizing with the pv system midway then presents equal power distribution problems to both properties even though the distance to any house is now cut in half as you still need to send power to 2 houses in 2 different directions so nothing is saved in doing this.
I really wonder just how much you would save by having a double sized system to run two houses?
I think that in both the long and short term, ALL things considered, you'd be better off with two independent systems. Remember; good fences make good neighbours. Hey, it wasn't me that ran the @!*^*@!! batteries down!
Thx both for your responses. The houses are both in the family - one is mine and one is my father's so no problem there. But is sounds like neither of you think it's practical to run current that far. I know nothing about electricity and am just exploring options. But if I can't ship electricity 600 feet, how does the power company manage..... no need to answer, just one of those 'if they can, why can't I" questions.
i'll answer for you. they run much much higher voltages along the poles. there are lines in front of my house that are 69,000volts. it goes through transformers nearer to the area to be serviced and into all of the houses. some power lines are much higher in voltage than that too. that is the key is higher voltages to overcome the resistive losses sending power any distance incurs. you could run the pv power into inverters to make it 120vac, but the losses are still high when going the distances you are refering to. the power companies do incur distances like that, but they don't care of the losses as they aren't paying the amounts of money you will be for your power through pvs.
Are you on-grid or off-grid for utility power... If you are on grid and just intend to use Grid-Tied solar for power--you probably can do it with a Grid Tied inverter... Those operate at 240 VAC and you could probably put a transformer in circuit to up that to 480 VAC (standard home type wiring is usually rated to 600 VAC)...
Or even send DC the long distance as some of the Grid Tie Inverters operate in the 180 to 550-600 VDC range (Xantrex is one).
If you want off-grid power, then it is a bit tougher as battery systems and charge controllers generally are not at that high of voltage (and therefore, you need more copper (or aluminum) to carry the current without too much losses).
And, given the size and location of the project, you will have to be very careful with lighting protection.
Lastly, it also depends on how much power you intend to generate/use... If this is a pure grid-tie system, then the maximum power will be whatever the ratings of the solar panels/inverter are (3 kW, 5 kW, etc.)... If this is an off-grid system, then the current ratings will be dependent on what you are running (a few lights, TV, stereo--or will it be a deep well pump, forced air heat/AC, washer/driers, lots of lighting, etc.)... The amount of current required will determine how much per foot it will cost you to string the power to your homes.
Here is a nice link that discusses many of the issues with running circuits to out-buildings (based on old 1999 NEC--but it is a good place to begin):
I would talk with an electrician to see how much it would cost you to run the cables you need (and if there is an accepted method for sending power the distance you need)--and cost out the alternatives.
-Bill "I am not an electrician" B.