Thoughts on Solar

Recently, I was talking to a client of ours about why they were so fortunate to be going solar as a Pasadena Water and Power (PWP) customer instead of being an SCE customer.  He expressed confusion when I said this, because everything that he had heard made him think the opposite was true!  That made me realize that some education was called for; hence this post!

I can think of three key reasons why going solar in PWP territory is more desirable than it is with SCE:

• True net metering;
• Tiered, not time-of-use rates; and
• No batteries needed! 

There are others - to be sure - such as the ease of dealing with the respective bureaucracies, but for now we will focus on these big three.  Let’s take ‘em one at a time.

True Net Metering

As readers of this blog know only too well, last year brought draconian changes to how solar system owners in SCE territory got compensated for energy that they put onto the grid.

WHAT SOME FOLKS SEEM TO HAVE MISSED IS THAT THESE CHANGES DID NOT AFFECT
PWP CUSTOMERS - AT ALL!!! 

PWP customers who install solar get full retail value for every kWh that they put onto the grid, which ranges from 20¢ - 33¢/kWh, based on the tier that you are in (more on that in a moment).  Pity the poor folks in SCE territory who are getting closer to 7¢/kWh.

PWP is not governed by the California Public Utilities Commission (CPUC) so their shenanigans in San Francisco do not torment us.  Rather, it is the Pasadena City Council that has the final say in how solar customers are treated, and let’s just say they have your back in ways that the CPUC clearly does not!

Tiered Versus Time-of-Use (TOU) Rates

SCE is forcing all of their customers onto TOU rates and that means that energy used between 4 p.m. and 9 p.m. can cost more than double what it does during the other hours of the day - as much as 61¢/kWh! Ouch!  Of course, most of the year, your solar system is not producing anything during that time period. 

But in PWP territory, the excess energy that you put onto the grid helps drive you out of the top tiers and lowers your overall bill.  Tiered rates are the most beneficial for solar, and PWP has them!

No Batteries Needed!

Batteries - or to use the more technically correct term Energy Storage Systems (ESS) - are costly, take up a lot of space on the wall, and in some areas - Altadena we’re looking at you - there are crazy restrictions on where they can be placed.  Sadly, if you are an SCE customer, the double whammy of no net metering and TOU rates, means you almost have to add an ESS to make going solar sensible.  Oh, and SCE’s power goes out - like a lot.  So having batteries can save you money in the long run and be there when the grid goes down.

Meanwhile, because energy from PWP isn’t priced based on when during the day you use it, you don’t need to store it during the day to offset costs from 4-9 p.m. (What is known as time-of-use arbitrage.)  Moreover, since you get full retail credit for every kWh you put back onto the grid, the grid itself acts very much like a battery for you!  Plus, PWP’s grid rarely goes down - Public Safety Shutdowns are unheard of in PWP territory, but they are a common occurrence for some SCE customers, especially at times of high winds or high heat. (It is 108 as I write this - yikes!)

TL;DR

PWP customers have it sooo good when it comes to adding solar! And while it is too late to save you from that crushing bill you are going to see in October, acting now means you will reap the benefits of adding solar for the next 20+ years! Let’s get started, shall we?

While you weren’t watching, SCE - the same SCE that is trying to kill off rooftop solar - just raised their Time-of-Use rates for residential customers. We will break down the increase and show you what it might mean for a couple of potential solar clients.

What are Time-of-Use Rates?

Time-of-Use (or TOU) rates are exactly what they sound like: a rate structure where how much you pay for energy is tied to when you use that energy.  (We wrote a lengthy blog post explaining the differences between TOU rates and Tiered rates, in gory detail!) 

The most common TOU rate for SCE’s residential customers is titled TOU-D, with the 4-9 p.m. window having the highest rates overall.  Compared to a tiered rate -  where your monthly bill is divided into steps based on the volume of energy that you use, with each volumetric step, or tier, bringing you a higher rate - a TOU rate does not increase on volume but on the time of day.  As a result, rates during peak periods can be 50% or more higher than the lowest periods.  Of course, that peak period - either 4-9 or 5-8 with SCE - corresponds to when people generally use the most energy!  Gotcha!!! (Those rate differentials are what provide the economic benefit of adding storage, and make simple strategies - like delaying the dishwasher or EV charging until out of peak rates - effective at saving money.)

How is SCE’s TOU Rate Changing?

Needless to say, SCE’s rates are very complex, with the energy charge being comprised of some eleven different components!  I will spare you those distressing details and just focus on the overall energy charge and how it has changed, as shown in this table:

SCE’s TOU-D Rate change for the 4-9 p.m. option.

On average, we see that rates here have increased between 3.67 and 3.80% over the prior rate, but there are some special gifts to solar customers buried in the rates.  When the Net Metering rules were changed a few years ago, it introduced the concept of Non-Bypassable Charges (or NBCs) - components of the rate structure that solar customers paid for every killowatt hour pulled from the grid, even if that same kWh was netted back by energy exported to the grid.  Far and away the largest NBC is the Public Purpose Programs charge, and in this rate increase it jumped from 1.323¢/kWh to 1.622¢/kWh - a whopping 22.6% increase! 

Another fun fact for SCE customers who have endured so called public-safety shutdowns, is that they are paying 0.6¢/kWh toward the “wildfire fund charge"!  That’s right, SCE’s customers are helping to pay for an insurance fund against wildfires caused by SCE, PG&E, and SDG&E - now isn’t that almost enough to get one hot enough to, well, burn!

Use Case Impacts

We decided to examine how potential clients would see their bills, and potential savings, change under the new rate structure.  As always, we made use of the wonderful tool Energy Toolbase to do our calculations. 

Our first example is a pretty average user in the Run on Sun service area, consuming approximately 30 kWh of energy per day, pre-solar.  Under the old TOU rate their annual bill pre-solar was $2,946, but under the new rate (including things like utility user taxes, etc.) their bill would go up by nearly 5%, an extra $144 for the year.  However, their post-solar savings also increase, by 5.42% or an extra $143 per year.  For this average user, adding solar ended up being a nearly perfect hedge against the SCE rate increase!

Our second user does not fare quite as well.  This is a significantly larger user, consuming more than 50 kWh/day.  Their pre-solar bill increases by 4.29%, or $228. Unfortunately, while their overall savings increases, it is not as dramatic as it is for the smaller user, reducing the differential from $228 to $92, compared to reducing it to just $1 for the average user.

Bottom line - adding solar helps hedge against rate increases, and as energy costs get higher, your annual savings will increase!

Meanwhile, SCE is Trying to Kill Rooftop Solar

It is one thing for SCE to be seeking, and getting, rate increases from the CPUC - that is their business model.  It is quite another thing for them to try and gut the value of net metering, thereby eliminating the economic value of adding solar - but that is precisely what they are trying to do!  We are fighting back, starting with a signature campaign targeted at a petition to Governor Newsom. 

There will be lots more to do in the coming days to fight against SCE’s attack on solar, but for now there is something simple that you can do - mash that button below and go sign the petition!

A client of ours noted that Pasadena Water and Power (PWP) offers, in addition to its regular, Residential tiered rate structure, the option to switch to a Time-of-Use rate structure, and he asked if he would derive additional savings from making that switch. Turns out that is not an easy question to answer, and there certainly isn’t a “one size fits all” result. We decided to take a closer look into these rates both for PWP and for the folks in Southern California Edison (SCE) territory.

SPOILER ALERT - The following is pretty much down in the weeds.  You have been warned!

Defining Tiered and Time-of-Use (TOU) Rates

Let’s start by defining our terms. Most residential electric customers, of both PWP and SCE, are on a tiered rate structure. That means that there are two or more cost steps - called tiers - for the energy that you use. Tiered rates assume that there is some minimally expensive charge for the first allocation of energy per billing cycle, and that as you use more energy your cost for energy increases. For example, SCE’s Domestic rate has three tiers and in the first tier the charge is 8.8¢/kWh, in the second tier the charge is 16¢/kWh, but the final tier is 22.4¢/kWh! (There  is also a non-tiered component that adds another 6.9¢/kWh to the customer’s bill.)

PWP, on the other hand, has a somewhat perverse tier structure in that the lowest tier is very cheap, 1.7¢/kWh, the second tier is significantly higher, 13.5¢/kWh, but the final tier actually goes down to just 9.9¢/kWh! Since the whole point of tiered rates is to provide an incentive for heavy users to reduce their usage, PWP is actually rewarding those who consume more than 25 kWh per day with lower rates! Very odd.

Time-of-use rates, on the other hand, are generally not tiered. Instead, the day is broken up into segments and the cost of energy varies depending on the segment in which it is consumed. PWP refers to these segments as “On-Peak” (from 3-8 p.m.) and “Off-Peak” (all other hours). But PWP’s TOU rate retains the tiered element as well, making it a truly odd hybrid rate structure.

SCE’s approach is more involved, dividing the day into three, more complicated segments: “On-Peak” (2-8 p.m. weekdays - holidays excluded), “Super Off-Peak” (10 p.m. to 8 a.m. everyday), and “Off-Peak” (all other hours).

For both PWP and SCE there is a seasonal overlay on these rates, with energy costs increasing in the summer months (defined as June 1 through September 30).

(It is important to note that both PWP’s and SCE’s TOU rates put the most expensive energy in the late afternoon to evening time period - pricing energy to offset against the “head of the duck.” Ultimately, these rates will create the energy storage market in California, but that is a post for another day.

Analyzing the Benefits of a Rate Switch - Pre-Solar

Assuming that one can create a spreadsheet to model these different rates (not a small task in and of itself!) there is one more hangup - data. Both PWP and SCE report total monthly usage to customers on their tiered rate plans - but in order to analyze your potential bill under a TOU rate, you must have hourly usage data for every day of the year! (Because there are 8,760 hours in a [non-leap] year, such a usage data collection is typically referred to as an 8760 file.)

The standard meters that PWP has installed simply do not record that data, so the average PWP customer has no way to know whether they would save money by making the switch.

On the other hand, most SCE customers do have access to that data and they can download it from SCE’s website.

After you create an account, login to it and go the “My Account” page. On the left-hand-side you will see some options - click on “My Green Button Data” (the too cute by half name for the interval data you are seeking), select the data range for the past twelve months, set the download format to “csv” and check the account from which to download. Then press the “download” button and cross your fingers - in our experience, the SCE website fails about as often as it actually produces the data that you are seeking!

Modeling PWP

Given that PWP doesn’t have data available, is there any way to estimate what the results might be? The answer is, sort of. We took an 8760 data set from an SCE customer and used that as our test data for both PWP and SCE. (The data file does not identify the customer.) Since the data file has an entry for every hour of every day, we can segment the usage against the On-Peak and Off-Peak hours, and using a pivot table - probably the most powerful took in Excel - we can summarize those values over the course of the year, as you see in Figure 1.

Figure 1 - Usage Profile for PWP

Summer months are highlighted in orange. For this specific energy usage profile, Off-Peak usage is more than twice that of the On-Peak usage (9,806 to 4,009 kWh respectively). So how does that work out when we apply the two different rate structures? The table in Figure 2 shows the details of the two rates:

Figure 2 - PWP Rates - Standard Residential and TOU

Under both rate plans, the distribution is tiered (with the perverse reverse incentive for usage above 750 kWh). Added to that is either the seasonally adjusted flat rate for energy, or the seasonally adjusted TOU energy charge.

Applying those rates to the Usage Profile in Figure 1 allows us to see what the energy and distribution components would be under both approaches. Given the hybrid nature of these rates, you might expect them to be similar and you would be correct. The distribution charge - which applies to both - comes to $1,180 for the year. The flat rate energy charge comes to $893, whereas the TOU charge is $985. Meaning that someone electing to use the TOU rate would have a yearly total of $2,165, whereas the flat rate user would have a total bill of $2,074, making the TOU rate - for this specific energy profile - 4% higher.

Beyond that, PWP has a number of other charges - such as a public benefit charge, an underground surtax, and a transmission charge - that are only tied to total usage, so the ultimate difference between these two rates is even smaller.

Modeling SCE

SCE rate structures are significantly more complicated that PWP’s. For example, the tier 1 (aka baseline) allocation varies by location. Since SCE covers such a huge and diverse area from cool coastal regions to absolute deserts, customers are allocated more energy per day in their baseline depending upon where they live. In the area around Pasadena that is covered by SCE, a typical daily baseline allowance would be 13.3 kWh in the summer and 10.8 kWh in the non-summer months. The baseline then is that number times the number of days in the billing cycle. Tier 2 applies to every kWh above baseline, but below 200% of baseline. Tier 3 applies to everything beyond that. As with PWP, the tiered rate only applies to “delivery” charges. The energy generation charges are the same all year. Here’s what that rate structure looks like:

Figure 3 - SCE’s Tiered Domestic Rate

The first thing that you notice when you look at this rate is how much higher it is than the rates from PWP, and the end calculation bears that out - the same usage that resulted in an annual bill of $2,074 in Pasadena becomes $3,227 once you cross the border into Altadena, South Pasadena, San Marino, or Sierra Madre - an increase of 56%! (There’s a reason why a growing percentage of our clients are coming from those surrounding, SCE-territory communities!)

So what would happen if this beleaguered client were to shift to a TOU rate? First, we need to re-parse the usage data according to SCE’s more complicated segmentation scheme, which gives us Figure 4:

Figure 4 - SCE’s Segmented Usage Data

Once again, the On-Peak usage is the smallest category of the three, amounting to just 23% of total usage, compared to 42% in Off-Peak, and 35% in Super Off-Peak.

Of course, SCE can’t do anything in a simple fashion, so they have not one but two basic approaches to their TOU rates, Option A and Option B.  Option A rates run from a low of 13¢/kWh (in summer Super Off-Peak), to 29¢/kWh (during summer Off-Peak) to an eye-popping 44¢/kWh (during summer On-Peak).  However, Option A includes a credit of 9.9¢/kWh on the first baseline worth of energy which reduces the monthly bill by roughly $30.

Option B deletes that baseline credit and replaces it with a “meter charge” (even though it is the same meter!) of 53.8¢/kWh/day, or roughly $17/month.  In return, the On-Peak charges are significantly reduced from 44¢/kWh to just 32¢/kWh.

So how does this shake out?  The results are quite surprising, as shown in Figure 5.

Figure 5 - SCE Rate Structure Comparison

The two left columns show the month-by-month calculations for both delivery (the tiered component) and generation (the flat component).  The two right columns show the month-by-month calculations for the two different TOU rates.

The bottom line is striking: under TOU-A there is a savings of 5% over the tiered rate, whereas the savings jump to 19% by going to TOU-B!  That is a savings of $600/year just by changing rate plans - a switch that any SCE customer can make.

MAJOR CAVEAT: YOUR MILEAGE WILL VARY!

The results displayed here are entirely dependent on your actual energy usage and no two usage profiles are alike.   It is possible, even likely, that some usage profiles will see an increase in bills under either TOU option.

The good news is, that for a nominal fee,  this is an analysis that we could do for any SCE residential customer - we would just need access to your usage data.

So that completes our pre-solar analysis. In our next post, we will look at how these results change when you add a solar power system into the mix.