How Do You Merge Multiple Power Sources, including Grid, Genset, Solar, Micro-Hydro & Batteries

I am building a farm in the Philippines (http://MountainAir.Farm). While there is grid power here, it is extremely unreliable and about double the cost of electricity in the USA.
• Local grid power is 240vac, 60hz, single phase (not split-phase like USA)
• I already have a 6500kw diesel genset which has the capability to be started automatically via an ATS. Even those my genset is relatively new, I am learning it is not highly reliable.
• There is a nearby (0.5 kilometer) spring-fed stream that runs 24/7/365 that I could possibly purchase.
• I likely will be able to drill a deep well (~300ft) from which I expect significant artesian (pressurized) water flow.
• I have ample room to build a small solar farm.
• I have already built a small structure suitable to house control equipment, genset and batteries.


  1. Reliable Power - I will have aquaponics and aquaculture tanks with both water and air pumps. While a few minutes of power loss is not critical, a few hours or days of outage would jeopardize the lives of both plants and fish. Also do not want to be without AC, computer, or internet.
  2. Economical Power - Since local power is about double the cost of power in the USA, my “guess” the capital expense of alternate power would have a reasonable payback period.
  3. Automatic Power Management - This means turn on the generator if I am not generating sufficient power with Micro-Hydro and Solar. This means turn off supplying power to the grid if I am draining the batteries. Maybe other things I have not thought of.
  4. Make Ice - If I have excess power, I want to make ice that can be sold on the local market using essentially free power.
  5. Sell Power To Grid & Possibly Neighbors - I don’t want to count on this a lot because when the grid is down, I can’t sell power. But selling excess power would still be wise.

Power Source Plan

  1. Micro-Hydro, probably in units of 1000watts. Would hopefully start with at least 2. Voltage from the Micro-Hydro to my powershed would be 480vac/60hz… this allows savings in electric wire and reduces transmission loses. Depending on the costs of Micro-Hydro vs Solar… I would add more to augment.
  2. Solar. Depending on the costs of Micro-Hydro vs Solar… I would add more to augment MH.
  3. Batteries - At least enough to bridge the time gap to genset startup. Maybe more depending on the costs of Micro-Hydro vs batteries vs Solar to handle peak loads.
  4. Grid - Two way transmission.
  5. Diesel Genset - This is a necessary and expensive pain in the rear. I certainly would not want to sell power to the grid with power generated by my genset.

But the big question is just how to go about connecting/merging all these various power sources in a logical and cost efficient manner. Can anyone recommend the equipment and setup that I would need?

Wow, sounds like an fun/challenging project @Ronny_Mauldin.

I was just in the Philippines, you get some pretty wild weather there, and I was amazed looking at the power lines how the power even held up as well as it did. Most nights the power went down, but the gen in the hotel kicked in pretty quick.

To answer your main question, you probably want something like the Selectronic SP Pro It’s an Australian unit, and very good. It’s basically the smarts of a system like this, and can integrate a bunch of different inputs and outputs. The Australian electricity grid is also 240V and single phase. Jason has done a review on it here

I think that you probably want to get an Australian solar company to consult you on this and do the design.

Good luck.


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The “electric power” in the Philippines is a mixed bag with years of stupid rules, graft, corruption and officials who simply do not care… unless they stand to make a few pesos.
The old cities have 220v 60hz split-phase power (110/110)… much like the 220 in the USA. The newer cities and rural areas typically have 240v 60hz single phase / multiple grounds. For economy of breakers and wiring, this “240v 60hz single phase / multiple grounds” is the best option in the world IMHO.
My power at the farm is 247v and is on a co-op transformer… and if everyone on the co-op does not pay their electric… they cut the whole co-op off. So I am going to have to buy my own 15kw transformer that connects to grid voltage.
Thanks for the info on Selectronic, I will continue to read more about them and then contract them for more information.

May be you should talk to these guys: