10 X Condo's sharing wind/solar grid.

Re: 10 X Condo's sharing wind/solar grid.

You are probably fighting an up-hill battle on your proposal... And where you are located also makes a big difference--Are you in the Fiji/South Pacific area?

My two cents... Look at designing a battery system that can handle ~6 days of average load. This will be the core of your system. You then need to decide how you are going to power the condo's... One (or several) large UPS's, or 1 per condo small UPS's...

Next... Getting power into the battery system. Solar RE systems only make sense if they power occupied units (or average power) over ~9+ months of the year. If the condos are only occupied for 3 month of the year--the fixed costs of solar, wind, etc. are very high vs the amount of power consumed (you can only store about 3 days worth of power in your battery bank assuming 50% maximum discharge).

With the battery bank in the "Middle" of your system design--you now have a "Hybrid" system. You can connect solar, wind, and diesel generator. And build out the system as makes sense (add your wind turbine--see how it performs;put an Amp*Hour meter on it--add some solar, see how that performs, etc.).

Also, even if a genset is the decision--the batteries will let your complex have power during the day (when it may not be worth running the genset because the power needs are low)--and in the evening when everyone is home, cooking, lights, tv, stereo, etc. is running... You can run the Genset at 50%+ rated power to supply the AC loads and bring the batteries back up to full charge.

The Hybrid Generator system has been used in Africa with good results... Supports light loads (computer, radio, music) during the day from battery bank, and heavy loads in the evening with genset (plus battery charging)... Can save a lot of fuel (50% or more fuel reduction--depending on power usage pattern and diesel loading). Even without solar RE/Wind.

Once you have the core system running--then adding solar RE (wind, solar PV) can be done in stages to reduce overall genset runtime and demonstrate cost effectiveness...

Regarding metering... You are talking about $1-$2 per kWhr (USD) at least for off-grid power (probably more depending on your local cost structure). Metering each unit might make sense--but just adding a $5 per night energy charge might make sense too.

A lot depends on the "owner/members" of your association. And such a system will need maintenance (battery care and replacement, generator servicing and fuel, monitoring to ensure everything is running OK, warning residences on excessive usage (electric hair driers, TV/Lights/Fans left on and nobody home, etc.).

Generally, extreme conservation is important to make economic sense for off-grid systems. And having a mix of user/owners makes things difficult to sort out and fund.

Regarding Wind Turbines--they are expensive to properly install and maintenance heavy (pull down once or twice a year just to inpect, lubricate, and tighten bolts). If it is mounted on a 20-60 meter tall tower (60' / 18 meter minimum recommendation, at least 10 meters above any trees/buildings/etc.)--the costs of just servicing the unit can be high. Let alone trying to keep a mechanical device running smoothly in a marine environment.

-Bill

PS: I am not a believer in small wind turbines at all--they tend to be unreliable and generate little output (especially if mounted on short towers)... Solar Panels, while expensive, have almost no maintenance requirements and produce power reliably day after day (assuming in a reasonably sunny location, clear of shade).