Hello from Phoenix

[wblanford]

I have been reading on this site for a while. I am considering PV Solar in Phoenix, realizing that I may be two years too late for SRP.

I have been considering a 3 kW ground mount array backing up to my south facing rear block fence on my cul de sac lot. The front of my two story house faces ssw but has may angles on the roof which would require a patch work of panels. I have a couple of quotes for 3 kw installations, but suspect that to make this work will require a low investment.

I have researched the SRP demand rate for solar. Currently I am on the TOU rate and used 19,000 kWh last year with a total $2185 bill. I calculated that my bill would have been about the same on the demand rate. That was with a high monthly demand of 8.5 kWh and average demand 6.4 kWh for the 30 minute peak interval. This was without limiting my demand usage. I have considered going on the demand rate without solar to save money. The secret would be controlling my demand. Unfortunately, my wife's views conflict somewhat with my demand plans. The demand rate has a summer peak rate of $0.0633 / kWh and off peak rate of $0.043 / kWh. This means that a 3 kW dc system would produce perhaps 5200 kWh annually saving $260 at an average rate of $0.05 /kWh. The main benefit of Solar may be to reduce the demand charge.

I would like to see some local Phoenix Solar installations and get some recommendations on cost effective installers.

[randomuser]

Welcome to this forum. I envy the amount you're charged for electricity.

[wblanford]

The $/kWh is low, but this is also the rate one is credited for power produced.




The demand charge is where SRP makes its money and that cannot be reduced by producing excess power.

On-peak demand charges (per kW)
	First 3 kW	Next 7 kW	All add'l KW
WINTER (Nov.-April)	$3.41	$5.46	$9.37
SUMMER (May-June and Sept.-Oct.)	$8.03	$14.63	$27.77
SUMMER PEAK (July-Aug.)	$9.59	$17.82	$34.19

The monthly service charge, which helps cover the costs of grid access and maintenance, is $32.44 on this plan for most residential customers. It is $20 on TOU.

For the past year, if I had been on the demand rate, $712 would have been the demand charge, and $389 for 12 months service charges. Adding the 9% tax, the annual charge before kilowatt charges would be $1200. The only way to reduce this is by demand control.

The demand plan seems to encourage high usage and discourage high demand.

[Ian S]

Solar no longer appears to make financial sense in SRP territory. If you can get a 3kW install done for $1.75/W after tax credits, that would be amount to a 20 year payback if I use your annual savings estimate of $260. Not very attractive IMHO. As for the demand charge, the problem is that the on-peak rate goes all the way up to 8 PM in the summer. Typically, your AC needs peak after 5 PM and solar, in the absence of battery storage, won't help much then. The problem also is that one high demand number during the month screws you for that month. I know since I was on an APS demand rate for many years prior to installing solar. It can be very frustrating.

[wblanford]

One of the solar quotes I received included a $3600 demand controller. It basically monitors total power from SRP and cuts back on the water heater, heat pump and dryer to limit the demand to the selected value. I already have my water heater, and pool pump on timers. I have considered building a relay box that could limit my heat pumps to allow only one to operate at a time. It could also monitor the dryer and oven to switch off the heat pumps. I can monitor my hourly usage on SRP's website. I may try this for a while. I can switch to SRP's demand and switch back in 3 months and be credited the difference if the demand rate bill is higher. Although I believe I could save money on the demand rate, getting buy in from my wife would be a challenge.

[azdave]

I can switch to SRP's demand and switch back in 3 months.

I'm with SRP but very fortunate to get grandfathered under the old rules. I would never go solar with todays requirements.

I'm confused about your comment about switching to demand and then back if you choose. I thought all new RE customers had no choice but the single E-27 plan with no option to move to other TOU plans with or without demand features?

SRP Price plans (E-27 on Page 28)

http://www.srpnet.com/prices/priceprocess/pdfx/TempNov2015RatebookPUBLISHED.pdf

[wblanford]

As long as I do not have solar, I can voluntarily switch to the demand plan and back to TOU. I suspect that I could save money without solar by switching to the demand plan.

Dave, some time I would like to see your setup in Gilbert and get the name of your installer. Is there a number of posts I need before I can pm you?

[randomuser]

Private messaging is turned off on this forum.

[azdave]

As long as I do not have solar, I can voluntarily switch to the demand plan and back to TOU. I suspect that I could save money without solar by switching to the demand plan.

Dave, some time I would like to see your setup in Gilbert and get the name of your installer. Is there a number of posts I need before I can pm you?

Okay. I thought your were saying you would be able to switch back and forth between plans once you went solar with SRP but that is not true under the new E-27plan required for all new RE customers.

My system is simple. 6.63kW with 26 panels facing due south on a 22-degree tile roof. Two identical strings of 13 with a very minor shade issue early in the morning during the dead of winter. The inverter is inside my relatively cool, north facing garage. I have other system monitoring besides the SRP provided data but the SRP info is so good I rarely look at the other data collection these days.

[wblanford]

I just signed up with Salt River Project in Phoenix for rate plan E-27P, Pilot Rate Plan For Residential Demand Rate Service. SRP changed out my Time of Use meter to a Time of Use with Demand meter. Not having solar, I can try out this rate plan for 3 months and if it costs more, I will be reimbursed for the difference. I can also change rate plans at any time. If I decide to install PV solar, this is the rate plan that is required for new SRP solar installations.

I will see if I can save any money with a much lower energy per kWh rate, combined with a higher monthly charge and a demand rate charge. If it was just me, I would definitely save money on this rate structure. My wife, who is at home during the day, agreed to this rate structure as long as she does not need to make any changes to her routine or temperature settings.

In analyzing the rate structure, see post #3, the average Off-Peak energy rate for the year is $0.0389 per kWh. The average On-Peak energy rate for the year is $0.0483 per kWh. On-Peak hours from November through April are 5am-9am and 5pm-9pm Monday-Friday. On-Peak hours from May through October are 1pm-8pm Monday-Friday. The power offsetting benefit of solar production from November to April is all Off-Peak or about $0.04 per kWh. The power offsetting benefit of solar production from May to October is I/3 On-Peak and 2/3 Off-Peak or about $0.043 per kWh. The solar installation cost/watt needs to be really low to provide any return.

Adding 9% tax increases the average annual rate to about $0.045 per kWh.

This would be a great rate for Electric Vehicle charging.

[wblanford]

This is my two month update after switching to the SRP E-27P Demand Rate.

SRP Rate Comparison
May-16	kWh	E-23 Standard	E-26 TOU	E-27 Demand
On Peak	211	$77.14	$41.29	$10.25
Off Peak	1012	$58.63	$74.69	$37.55
Demand	3.5			$31.41
Service		$20.00	$20.00	$32.44
Subtotal		$155.77	$135.98	$111.64
Tax 9%		$14.02	$12.24	$10.05
Total		$169.79	$148.22	$121.69
D Savings		$48.09	$26.52
Jun-16	kWh	E-23 Standard	E-26 TOU	E-27 Demand
On Peak	310	$77.14	$60.67	$15.07
Off Peak	1327	$105.04	$97.93	$49.23
Demand	4			$38.72
Service		$20.00	$20.00	$32.44
Subtotal		$202.18	$178.60	$135.46
Tax 9%		$18.20	$16.07	$12.19
Total		$220.37	$194.67	$147.65
D Savings		$72.72	$47.02

Since I was previously on the TOU rate, I saved $26 in May and $47 in June with the Demand rate. Due to the low rates for On Peak and Off Peak usage, the main effort is to control the highest peak demand during On Peak hours (1 pm to 8 pm) for the month. Hot water heater and pool pump are on timers, so are only operating during Off Peak hours. The upstairs heat pump is programmed to only run during Off Peak hours. May was a hot month with 118 degrees being the hottest day, the down stairs heat pump runs as needed to maintain 80 degrees. The main variable was cooking energy, with the oven contributing the most. We are definitely cooking more on the outdoor grill. My wife does not like the demand rate, but has been supportive with shifting her usage toward off peak hours.

Note that the SRP Solar Estimator on the SRP web site estimates the savings with solar by comparing the savings on the Demand rate with solar to the Standard rate without solar. Most of the savings will be due to controlling the demand, which may be independent of solar.

It is definitely taking more effort to limit the peak demand and learn how to spread out the usage. Hopefully the process will require less effort over time.