New APS rate plans are good for solar!

Sounds like good news. Any suggestions as to a method how Joe/Jane 6 pack can might be able to estimate an annual bill, or ways to avoid demand charges ?

I got my APS application approved June 30th so I just got in under the wire (pun...so to speak) in anticipation of getting on the old net metering plan for the next 20 years.- do you recommend staying that course or switching to a new plan? I have until Feb to finish my project (6kW ground mount system - Cochise County)

Go ahead and get your system grandfathered, see how your bill runs for awhile and then you'll be better able to evaluate if the new rates are better.

I say it would be a very rare instance where the the new rules for RE customers would be a benefit over keeping the old. In CA it seems like you need an advanced math degree to figure it all out.

I'm in Phoenix but with SRP instead of APS. I'm extremely fortunate that I'm grandfathered under the pre-2014 SRP plans. No TOU for me. All energy credits go into one bucket to be used anytime I desire for up to one year. TOU was far worse as I banked way too much off-peak energy and hardy any on-peak was ever banked. You also could not swap one for the other, ever. The annual account zeroing in April results in enough cash credit that I don't even pay a connection fee until November. The rest of the year I pay $21 monthly for the connection.

Today, with the plans offered for RE customers by either APS or SRP, I would not install solar. The payback is far too long and solar was a financial decision for me.

Remember if you switch anything now APS will void your 20 year grandfathering. Currently you are guaranteed to be paid at full retail for 20 years. If you switch it's 10 years and then an unknown number that gets lower after 10 years.

https://www.svssolutions.com/hubfs/S...a-166e6927262f You can figure out how much your Arizona APS Electric bill will go up each month with the new rate plans that start May 1st with this Analyzer.

Not sure what you mean by 'change anything' - I did have to change a couple things due to APS Engineering request (EIT red-line demands, 3 mo after approval actually) and I upgraded my wire size to meet code and changed my breaker size to protect the increased wire size. So yes I have changed things but the size of the system has remained the same.Because of the EIT delays I asked for a deadline extension and was told OK- but I may not need it as the electrician did the hookups yesterday and I only have a few nitnoids to finish before calling for inspection. Then to see about the tax credit forms....

Being grandfathered into net metering sounds like a good thing. I sure like the simplicity of it myself. If the utility is offering you a voluntary switch to a different arrangement, then it's in their interests for you to do so. They're not going to offer you something that costs them more on average and in the long run.

An aside: Considering how much electrical power is consumed in Phoenix by air conditioners that are cranking away more during the day than at night, I would think that rooftop solar will ultimately be viewed as a useful resource by the utilities. They can't expand Palo Verde, and the water levels are dropping at the big hydro dams. Meanwhile, it's getting ever hotter and the population there never seems to stop growing.

PV might be viewed by the POCO as having some marginal and perhaps additional benefit, but only in combination with some on site or local storage of the PV generated power to bridge the gap between max. PV generation times of mid day and max. grid demand times of late afternoon/early evening.

I don't see much on the demand side that would change the POCO's view of the current situation, or their opinion with respect to distributed, or for that matter central PV unless storage could help flatten the demand curve, and that could be done without PV.

I mean if you change your APS plan from standard or whatever you currently have to one of their new 6 plans. That will void your 20 year grandfathering.

I know a guy who runs his AC at night and cools the house way down before the heat of the day begins because the power is cheaper then. I wonder if something similar might eventually be encouraged by APS and SRP for rooftop PV customers: Run your AC from your own PV generated power (with sunshine but early in the day before the grid really gets loaded) and get a premium discount for freeing up generating capacity.

It is called Super Cooling we do that here in Arizona when off peak is 6 cents a KW but in May the rates go up and it will be almost 11 cents off peak so it won't be as feasible.

It's a technique that's been around as long and in as many places old and new as thermal mass. Funny how things keep getting (re)discovered. A very simple and elegant concept.

Works best/most efficiently when a high thermal mas is combined with a low building heat loss coeff. (Effective building thermal mass per deg. of temp.)/(building hourly heat loss coeff.) = the building time constant in hours, with the goal of no more building internal temp. change than desired for the time period under consideration (off peak to on peak, or over a peak period for example), with consideration for the design temp. diff. inside to outside.

The concept works the same as or very similar to capacitor charging/discharging in a D.C. circuit with inside to outside temp. diff. analogous to Voltage on either side of the capacitor.

Stretching the building time constant to its limit, it's theoretically possible to have a large (long) enough time constant to store excess heat in the building mass or thermal storage device in summer and use it all winter. That's mostly impractical, but some yahoos who don't read/learn from what others have found out the hard way persist on dreaming and building thousand ton concrete houses and covering it with straw bales, etc.

FWIW, they're usually some of the same folks who confuse thermal mass with thermal insulation. Thick concrete walls by themselves are lousy insulators.

The practical limit for thermal time constants and thermal mass seems to be ~ 10 days to 2 weeks or so depending.

For time shifting as a scheme for gaming a T.O.U. tariff, and mostly because most residences are thermal sieves, it's probably a lot more cost effective and practical to reduce the building heat loss coeff. by tightening up the building envelope as a first step rather than add thermal mass. BTW, forget new windows as a cost effective measure. They simply aren't because they cost too much. Instead, buy a case of caulk for starters and use it from the inside out.

Simply subcooling a building to, say, 65 F. and letting it heat up through any peak pricing period can cause problems beyond simple comfort considerations that won't be immediately apparent and probably won't save as much $$ and certainly not as much electricity as might be thought. Reduce the heat loss and stretch the building time constant that way. You'll save twice.

To be even talking about 0-600kwh or 600-1000kwh makes me envious of your northern location. Phoenix consumption I get below 1000 in winter and see 3000+ in summer.

I'm opting for the saver plus plan with the cheapest off-peak, as we use tons of ac overnight and with west facing solar, I have no problem turning up the thermostat just for the last two hours of the day.

Demand charge will probably still be 3 or 4 kwh but the saving on off-peak consumption more than offsets that. APS probably won't approve my interconnect until January or February so I'll update then with results of the new plan and west solar.