Re: [hreg] grid tied system with battery backup?!
- A lot og generators may not be inverter compatible. the "condition" of the voltage can shut down some inverters. It's helpful to do some research first or else have the genny separate from the inverter all together.If you plan to connect a compatible generator to the inverter input, be sure that the genny has a "two wire" start circuit. A three wire will cause headaches and require more equipment to make it all work automatically.Jim----- Original Message -----From: Gary BeckSent: Thursday, October 30, 2008 8:29 PMSubject: RE: [hreg] grid tied system with battery backup?!
Honda sounds like they are on top of the needs of the buying public. I will have to spec them into any new home designs. HomeDepot has natural gas units for about $250 per kilowatt - but I think they are without any autostart/disconnec t.
I once tried to get a Capstone microturbine (70 kW) into the design a proposed retirement community development for shelter-in-place power capability for a protected load during a hurricane outage. For $1000/killowatt (uninstalled) your could get a whole auto connect/disconnect a 'dual mode controller' microturbine generator package from Capstone.
The 'dual mode controller' could automatically transfer the microturbine from grid connected operation to isolated or standalone operation when a utility outage occurs. They would run as long as natural gas was available - a few years continuous if needed since they had air bearings and no gears or oil. The DMC would monitor the grid and when utility power was restored, the Capstone DMC would synchronize with the grid phase and then automatically return the microturbine to grid connected service.
This same controller also allows the microturbine to be used as an automatically dispatched standby generator for critical power - only if you add a separate big UPS battery to take the load for the 10 second it takes for the microturbine to spool up. Six units like this are in downtown Houston. Capstones have their own big battery bank in the base to help convert AC to DC to AC. They also smooth the transition and to handle standalone power surges and spikes. But in the retirement project, the batteries ended up being the most expensive service item in the whole unit.
Gary Beck, P.E., SECB, LEED AP
4010 Blue Bonnet Blvd.
Suite 114 Houston, Texas 77025
Tel: 713-377-4209 Fax: 832-201-5338
From: hreg@yahoogroups. com [mailto:hreg@ yahoogroups. com] On Behalf Of Kevin Conlin
Sent: Thursday, October 30, 2008 1:04 PM
To: hreg@yahoogroups. com
Subject: RE: [hreg] grid tied system with battery backup?!
Christian, Outback Power Systems makes a grid tie inverter that also has provisions for battery backup. You do get the best of both worlds, but from a practical standpoint, after about 24 hours its best to also have a generator, as the battery bank for an extended outage will be very large and expensive, and the batteries do degrade over time even if they are not used very often. Honda has a new line of small, smart generators that could run off natural gas, they have provisions for battery backup and also have an automatic transfer switch to disconnect from the grid when the power goes out.
I wish I could give you more details, but Im really not in that aspect of the business. The info should be readily available online.
4007-C Greenbriar Drive
Stafford, TX 77477
Local (281) 340-1224
Toll Free (877) 340-1224
Fax (281) 340-1230
Cell (281) 960-8979
From: hreg@yahoogroups. com [mailto:hreg@ yahoogroups. com] On Behalf Of Christian Lofton
Sent: Thursday, October 30, 2008 12:41 PM
To: hreg@yahoogroups. com
Subject: Re: [hreg] grid tied system with battery backup?!
Check out this section of our website.
http://www.apowerso lutions.com/ index.php? p=1_39_Solar- Electric- Power-Battery- Backup-FAQs
On Thu, Oct 30, 2008 at 12:28 PM, Marc <marc.morgan@ gmail.com> wrote:
> Excuse my inexperience.
> My plan is to install a grid tied system next year. But after
> experiencing my first hurricane (and not having power for 3 weeks) I
> guess I need to rethink. I thought that having a grid tied system that
> the electricity generated would be usable if I had no power. But
> apparently that is not the case. All of the electricity generated goes
> to the utility company and that offsets the power used in the house.
> So if there is no connection to the utility company, a grid tied
> system is doing nothing for you. Is this correct?
> So here is my question. I know that you need different equipment for
> an off the grid system. But if I wanted to have a grid tied system
> with a 24-48 hour minimal backup battery source, do I need to just
> plan to buy an off grid system with fewer batteries? Or is this a
> common system that I just haven't found documentation about it.
> Any help would be appreciated.