The utility feed-in meters right off the inverter, then separately demand meter off of the load-side meter.
Which means I need to load shift the solar to offset the building loads just shy of net zero, then export the excess on the feed-in meter (because you can’t net meter). I could set it up with a bunch of small inverters and subarrays, and use contactors to switch A/B the inverters one at a time between the demand side and export side. But I thought there must be product solutions for this already. Any thoughts? > On May 30, 2016, at 9:08 PM, Mac Lewis <maclew...@gmail.com > <mailto:maclew...@gmail.com>> wrote: > > Hi Troy, > > Does this little utility have a Time of Use rate structure? How often do > they true up (pay the customer for their extra power)? > > There are various markets that this makes sense, Germany, Hawaii etc. They > call this type of system a self-consumption system. It does require energy > storage/management. There are quite a few companies out there that are doing > this now, Outback, Schneider Electric, Sonnen etc. The pricing that you are > stating $0.08 retail, will make this extremely difficult (impossible) to > offer any type of payback for a system like this. However, you can offer > excellent backup power and a "future-proof" system ready for almost any type > of rate structure. Some of these systems can also intelligently reduce > demand charges by exporting power out of the battery bank during high energy > use. > > What makes the most sense will really depend on the rate structure. If the > utility says that they will pay whole sale for overproduction, ask them how > often they check the meter. Do they net-meter? When is the check cut for > excess energy production? It's common for a utility to only pay whole-sale > for over-production, but allow you to off-set retail electricity rates. We > have a utility that used to pay off any excess in January. This was a rotten > deal for solar customers because they would get paid whole sale for what they > over produced in the summer in the dark days of winter would be buying > retail. They have changed this policy to have a continuous rollover option. > > Good Luck > > > On Mon, May 30, 2016 at 11:23 AM, Troy <tahar...@heliocentric.org > <mailto:tahar...@heliocentric.org>> wrote: > I am dealing with a small utility that only provides a small feed-in tariff > (basically wholesale). Customer wouldn’t have much value to install PV when > they sell in at 5 cents, and buy back at 8 cents. > > However, if we load shifted the PV to provide an internal offset on the > consumption meter (but staying clear of exporting), and move any excess to > the tariff meter we could make the PV more valuable by offsetting the 8 cent > power first, rather than just producing 5 cent power all the time. > > Has anyone done this? Are there legal hurdles? Any reason one can be legally > stopped from offsetting their own power? > > Thanks, > > Troy > Heliocentric > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > <mailto:RE-wrenches@lists.re-wrenches.org> > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org> > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm <http://www.re-wrenches.org/etiquette.htm> > > Check out or update participant bios: > www.members.re-wrenches.org <http://www.members.re-wrenches.org/> > > Thanks, Troy Harvey --------------------- Principal Engineer Heliocentric 801-453-9434 tahar...@heliocentric.org
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