Category: "Residential Solar"

08/20/20

  01:44:00 am, by Jim Jenal - Founder & CEO   , 761 words  
Categories: All About Solar Power, Climate Change, Residential Solar, Energy Storage

Behind the Meter to the Rescue!

It’s hot here in California, fry an egg on the sidewalk style hot, and the grid is feeling the heat.  The California Independent System Operator (CAISO) - the entity responsible for managing the grid - has issued warnings about possible outages, and even our local utility, Pasadena Water & Power, sent out emails to customers warning that cutoffs might be necessary.  The extreme conditions have prompted some extreme reactions, blaming the State’s shift to more and more renewables as the cause of the problem.  But overlooked in all of this is the contribution of local solar power systems, “behind the meter,” that have greatly improved the present situation, and with more aggressive utilization of storage, could do even more.  Here’s our take…

Blame Game

Let’s start by looking at what is causing the present problem. As we all know too well, we are in the middle of a pandemic and conditions in California have been depressingly awful, with a 7-day moving average of new cases at nearly 9,000.  As a result, a lot more people than usual are working from home, driving up electricity loads as we struggle to remain sane, and if possible, cool.  That’s been tough, as the entire state is in the grip of a week-long heat wave, with temperatures soaring above 100 degrees, and in some places, above 110!  All of that has created record demands for electricity and the grid has struggled to meet that need, with spot prices hitting all-time highs.

For those opposed to California’s efforts to “green the grid,” this provides an opportunity to go on offense. Cue Republican Assemblymember, and Vice-Chair of the Committee on Utilities and Energy, Jim Patterson:

You can’t run a 21st century economy that’s the fifth largest on the planet with wind and solar. I have been warning over and over again that the policies coming out of the democrat-controlled legislature and Governors’ office are creating the conditions for blackouts and brownouts and here we are seeing the evidence.

Wow, just how wrong can you be?  Let’s be clear: no 21st-century economy is going to survive the century if we don’t figure out how to do so with solar, wind and other, non-fossil fuel based sources of electricity.  And despite the predictable piling on from climate change deniers, there are multiple paths ahead for getting to an all-green electric grid.

Behind the Meter to the Rescue!

All of the stories about the blackouts, however, ignore the contribution - both present and future - of behind the meter resources, that is, local, rooftop solar.  Our friends over at CALSSA sent out the following graph that helps to make those contributions concrete:

Behind the meter solar and storage contributions to the grid

There’s a lot going on here so let’s break it down.  The brown curve is the actual reported demand data from CAISO on August 14th.  But without the contributions from the million plus behind-the-meter solar installations the actual load would have been significantly greater, as shown by the yellow line.  That is capacity the ratepayers of California did not have to purchase, but still benefited from its production.  Moreover, as the yellow line shows, the peak demand is actually at 3 p.m., but thanks to behind-the-meter installations, the peak on the grid is both lower, and later, a fact not often explained to the public.

The vertical lines mark the period last Friday that was subject to rolling blackouts - from roughly 7 to 10 p.m.  As the merger of the yellow and brown lines around that time indicate, solar production is no longer a factor.  But there is still a role to play as storage begins to be deployed with ever greater frequency.  CALSSA’s policy director, Brad Heavner (who created this illustration), notes:

If California builds 3 GW of additional energy storage systems at customer locations that can be dispatched during grid shortages, it would further trim evening peak needs. This is shown in the figure as the dotted blue line. CALSSA estimates the state can achieve this level of build-out within the next five years with state policies.

This is certainly doable, but it will take ongoing financial support, and preferably a more transparent rebate program than the present, byzantine SGIP program.

Ironically, the utilities are pushing their customers into purchasing more storage, as the public’s patience with grid outages - whether from rolling blackouts, or utility initiated public safety power shutoffs - is at an all-time low. As sophisticated products like the Enphase Energy Ensemble Storage system become available, more and more solar consumers will become storage consumers as well.  Once again, the ratepaying public will benefit from those investments, and hopefully all of us will be able to keep our cool!

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08/14/20

  02:55:00 am, by Jim Jenal - Founder & CEO   , 828 words  
Categories: All About Solar Power, Residential Solar, Energy Storage, Solar Repairs

Building on a Legacy: Enphase Opens Ensemble to Earlier Generation Micros!

On Tuesday, August 11, 2020, Enphase sent out a notice to its top installers alerting them that starting in December, the Ensemble Storage System would support earlier generation microinverters and not just the IQ series as had been originally announced.  We contacted Enphase to learn more, and here is our report…

Some Background…

Last November we wrote about the coming Ensemble rollout.  In describing how Ensemble could be incorporated with existing systems we wrote:

First, you need to have IQ microinverters.  At least as of the initial rollout of this system, the older microinverters are not supported.  That means that the M and S-series of microinverters have to be replaced to IQ-series microinverters to work with Ensemble.  (I do not know if this will change in the future, but it is the guidance that we are getting at this time.)  It is possible that there will be some sort of replacement program (like Enphase did with the legacy M-190 customers), but I have not gotten any word about such a plan yet.

As we were told by Enphase CEO, Badri Kothandaraman, at SPI last year, it was important for Enphase to focus on a successful launch of Ensemble, and the way to do that was to concentrate on pairing it with the more capable IQ series of microinverters.  It had been disappointing news, but understandable given the challenges of bringing a product as technically sophisticated as Ensemble to market.

So I was more than a bit surprised when I saw the announcement from David Ranhoff, Chief Commercial Officer at Enphase, that Ensemble would be able to support M215 and M250-based systems as of December!  Of course this raised nearly as many questions as it answered, so I reached out to Enphase for more details.  

What We Know Now

I was able to speak with Utsav Ghosh, Senior Product Manager, about the details behind the announcement.

Our first question was: What about the S280’s?  They are more capable than the M-series, so are they included?  Sadly, no, not at this time.  Given that the M215’s and M250’s are the largest segment of the non-IQ installed base, they generated the greatest number of inquiries, and so they got the staffing attention.

I remarked that given the relatively short window between when Ensemble was available for the IQ micros and when it will be available for the M-series, why not just say that they would be supported.  The answer, it seems, is that in refining Ensemble, they realized that it would be easier than previously thought to fold in the M215/250’s.  This, of course, gives me hope that the S280’s won’t be far down the line.  Squeak, squeak!

Enphase M215 microinverter will now work with Ensemble Storage System  Enphase M250 microinverter will now work with Ensemble Storage System 
Enphase M215 Microinverter is Eligible…  As is the M250 to work with the Ensemble Storage System! 
Alas, the S280 is out of the picture, for now! 
Envoy S

Our next question concerned communications - the M-series micros communicate via Power Line Communications (PLC) via the neutral and hot conductors.  The IQ-series does not bring a neutral to the roof, so it communicates PLC from hot to hot.  How does this get resolved?  

Turns out quite easily, assuming you have an Envoy-S, like the one on the right.  So how do the IQ8 microinverters in Ensemble communicate with the Envoy?  As it turns out, the same way that they do in an IQ system - via the add on Comm Kit that adds Zigbee capability to the Envoy-S.  The even better news is that Comm Kit is part of every Ensemble Storage System, so there is no additional cost for M-series systems over IQ systems!  Yay!  (The Envoy-S will need a new software version, but that is a free download.)

Our next concern had to do with speed issues: the M-series micros just aren’t anywhere near as computationally powerful as their IQ cousins.  Would the seamless backup functionality promised with the IQ series still apply?  Yes, we were assured.  Cool!

Which brought us to our final question: What ratio of legacy inverters to IQ8 inverters will be needed to allow the microgrid to operate?  Recall that with the IQ series we are presently being told that the ratio is 1.5:1, that is, an Encharge 10, that has 12 IQ8 micros inside, can support up to 18 IQ 6 or 7 micros on the roof.  (While we are hoping to see some movement on that front, that is the present design guidance.)  So what will the ratio be for the M-series?

Great question - no precise answer as of yet, other than “it will be more restrictive."  There is testing ongoing to establish precisely what those limits are, which is why the availability is being cited for December and not now.  Obviously we will be following this closely and will update you when we know more, watch this space!

I want to thank Utsav Ghosh for being so responsive and generous with his time.

And I especially want to thank Enphase for responding to the cries of their clients in getting this much-needed functionality addressed.  Great job, folks!

Now about those S280’s…

06/29/20

  07:47:00 am, by Jim Jenal - Founder & CEO   , 404 words  
Categories: Residential Solar, Net Metering

Update on Net Metering Attack at the FERC

Back in April we wrote about an attempt to eliminate Net Energy Metering - the primary economic benefit for rooftop solar - by way of a misleading petition filed with the Federal Energy Regulatory Commission (FERC). Here’s an update (h/t Utility Dive)…

The petition was filed by an entity called the New England Ratepayers Association (NERA) and if successful, would potentially affect net metering in the 45 states where it presently exists in one form or another.  The FERC regulates interstate electricity markets, and NERA portrayed net metering as a “wholesale sale” of energy, essentially subjecting rooftop solar systems as if they were utility power plants.  From NERA’s FAQ about the petition:

[N]et metering is having an unfair and harmful impact on ratepayers, especially low-and middle-income families. Given this problem, NERA has chosen to challenge net metering at the body which has the proper jurisdiction over wholesale electricity transactions.

Under FERC rules, the public had until June 15 to comment on the petition, and NERA found support from some usual suspects including the Heartland Institute (famous for its climate change denialism), the coal company Murray Energy (hilariously ridiculed by John Oliver a few years ago), the Competitive Enterprise Institute, Americans for Tax Reform (say what?), and Citizens Against Government Waste. 

Curiously, although several utility companies - including PG&E - had suggested that they would comment, none of them did.

In opposition was a very long and bipartisan group of people ranging from solar companies (well duh) and solar trade associations, to local state energy regulators.  For example, the National Association of Regulatory Utilities Commissioners (which includes the California Public Utilities Commission amongst its members) said in its comments:

The [FERC]… has for nearly 20 years acknowledged states’ authority and held that net metering does not involve wholesale sales subject to its jurisdiction… Relying on that settled law, states and utilities have developed and implemented net metering programs, and millions of Americans have made long-term investments in solar panels and other distributed generation for their homes and businesses.

Exactly!

Interestingly, Public Citizen dug up some IRS filings for NERA - which self-describes as "a non-profit organization focused on promoting sound public policy that protects utility customers, both families and businesses, and lowers the cost of regulated services” - that cast doubt on that claim.  According to the IRS filings, NERA consists of 15 members (identities not disclosed), ten of whom pay $20,000 in annual dues and five that pay $5,000.  Not exactly a grassroots organization!

Watch this space!

05/12/20

  06:41:00 am, by Jim Jenal - Founder & CEO   , 949 words  
Categories: All About Solar Power, Residential Solar, Energy Storage

New Rule in SCE Territory Makes Solar + Storage More Valuable

We just learned from our friends at Energy Toolbase that Southern California Edison has just changed a rule about how solar PV systems with Energy Storage can operate, and the result - amazingly enough - results in greater savings for our clients!  Imagine that?!?  Here’s our take…

It used to be in SCE territory that when you added a storage system to your PV array, you could not export energy from the storage system to the grid and receive net metering credit.  That meant that when the storage system was discharging, it could not exceed what the home’s loads were demanding.  If your usage in the evening was low, or say you were out of town, your fully charged battery could not discharge at all - a poor utilization of that expensive storage system.

But now SCE - along with the other IOU’s, PG&E and SDG&E - have changed their rules to allow storage systems to discharge back to the grid and receive full net metering credit for that energy, as long as the storage system is solely charged by the PV array.  When you combine that rule change with electricity rates that favor storage, such as SCE’s TOU-D-Prime rate, the change in the rule can account for significant savings.

To get a handle on how big a change this will be, we went back to the data that we have for a client who we will be installing a small PV array and a 10 kWh Ensemble storage system soon.  (All of our data analysis and visualizations you see here were done using Energy Toolbase, simply the best presentation tool on the market.)

Solar PV & Storage - No Net Metering Discharge

Our client with the small, 4.6 kW, PV system and 10 kWh Ensemble storage system has a system payback of 11.4 years.  (Larger systems would have a faster payback.)  For this analysis, we imported his SCE interval usage data (provided by UtilityAPI) into Energy Toolbase.  ET then takes the performance output from the PV system, the charge and discharge parameters of the storage system, and overlays that on the existing usage - doing that calculation over every fifteen minute interval for a year.

The graph below shows one day, July 8th, as a representative sample.  Let’s break this down:

Solar PV + Storage - no net metering discharge

There’s a lot going on in this image (click on it for a larger version).  The dark gray is the historical usage demand based on the SCE data.  The value is shown at the top as “Current Demand” and at the moment we have focused on - July 8 at 4:15 p.m. - the historical demand was 1.94 kW. 

The green curve shows the modeled PV array output, using the specific parameters for this site - azimuth, tilt, shading, historical weather, specific equipment being used - as determined by NREL’s PVWatts tool (version 5).  Right now it is at 1.17 kW. 

The red line shows the percentage state of charge for the storage system, at this moment it is 83%.  Net Demand is what is being imported (positive number) or exported (negative number) to the grid.  Finally, Battery Power is how much power is being pulled from the storage system which at this moment is 1.94 kW.  At the bottom is the cost parameters for this rate schedule.  Under the pre-solar Domestic rate (which is a tiered rate) the cost of energy is 18.7 cents/kWh, whereas under the new rate structure it is more than twice that at 38.3 cents during the peak, 4-9 p.m. period.

 So… earlier in the day, as the output from the PV increases, and energy charges are cheap, the solar charges the battery for use later when the rates are high. As we cross over into the peak rate period at 4:00, the storage system begins to discharge and its output is exactly the same as the demand, meaning that all of the power from the PV system can be exported to the grid. 

But note that the battery power is only 1.94 kW, even though its continuous peak output is roughly twice that, 3.84 kW.  Under the old rules though, the storage system cannot output more than that, since it is barred from exporting to the grid.  As a result, when the peak rate period ends at 9:00 p.m. the storage system shuts off, even though it is still partially charged (nearly 40% capacity remains in this example).

That’s leaving money on the table!

Solar PV & Storage - Net Metering Discharge Allowed

Consider the same day, only now we can export the full output of the storage system as desired to maximize our time-of-use arbitrage.

Solar PV + Storage - no net metering discharge

Everything is essentially the same until we get to 4:00 p.m. and then things get very different!  Look at the difference in the output from the battery system, it is now putting out it’s maximum sustained power of 3.84 kW, resulting in more than 3 kW being exported during the peak price period

More importantly from an arbitrage perspective, the storage system is completely cycled.  Meaning that we have gotten full utilization from our storage system investment.  

What does that mean overall economically?  Payback is reduced from 11.4 to 10.7 years, a 6.1% improvement.  Gee, thanks, SCE!

So why are they doing this?  Simple: grid support. Having storage systems maximizing their output during the peak demand period (remember the Duck Curve?) helps the utility to manage its load, and reduce the need for expensive peaker capacity. Everybody benefits: our client (with faster payback), the utility (with better grid load management), and even non-solar/storage rate payers (as they don’t have to pay for that additional production capacity.  Win, win, win!

Of course, these economic benefits don’t really apply to a tiered rate structure, such as is used for residential rates in PWP territory.  But if you are in SCE territory, adding smart storage, like the Enphase Ensemble system, just became a lot more lucrative.

04/23/20

  06:41:00 am, by Jim Jenal - Founder & CEO   , 725 words  
Categories: All About Solar Power, Solar Economics, Commercial Solar, Residential Solar, Ranting, Non-profit solar

While You Were Sleeping: Will FERC Preempt States' Ability to Regulate Solar?

For the most part, the regulation of the solar industry - particularly the residential and commercial solar industry - is a function of state regulators.  In California, both the California Public Utilities Commission (CPUC) and the California Energy Commission (CEC) have been the major players in shaping the policies that govern solar installations, including policies like Net Energy Metering (NEM) which determines the economic value of going solar.  But now, a petition from the other side of the country could change all of that, and force states to turn control over the solar industry to federal regulators.  Here’s our take…

FERC logo

The Federal Energy Regulatory Commission (FERC) is ”an independent agency that regulates the interstate transmission of electricity, natural gas, and oil.” Well, wait a second, what does rooftop solar have to do with the “interstate transmission of electricity"?  At first blush, certainly nothing - the excess power from your home solar might go to power your neighbor’s house, but it certainly isn’t crossing state lines. (As a recovering lawyer I could go into a lengthy discussion of the Constitution’s Commerce clause and how that has been broadly interpreted to cover an amazing array of things that seem local, but are actually interstate commerce - but I will spare you that discussion!)  

The hook here is in the greater detail of what the FERC does: “Regulates the transmission and wholesale sales of electricity in interstate commerce."  Under NEM rules, excess energy put out onto the utility’s grid by a “behind-the-meter” solar system, i.e., all grid-tied residential and commercial PV systems,  is then resold by the utility to its other customers.  A petition to the FERC filed by the New England Ratepayers Association is asking FERC to find that those sales are under the exclusive jurisdiction of the FERC.  From the petition:

The law is incontrovertible. The [Federal Power Act] draws a bright line between state and federal jurisdiction over energy sales. Sales of energy at wholesale are subject to the exclusive jurisdiction of this Commission. Sales of energy at retail are subject to the jurisdiction of the states. The sales at issue in this Petition are wholesale sales because the energy is being sold to the utility for resale to the utility’s retail load…  and therefore the Commission is required to exercise its rate jurisdiction over them. [Emphasis added.]

Wow!  Now that is interesting - energy exported to the grid, for which the PV owner is paid retail rates (or closer there to), and which the customer down the wire pays full retail rates, is somehow transmogrified into a wholesale energy sale!

But what is the point of all this?  Simple - if these are wholesale energy sales, then FERC has sole regulatory control, and pro-solar policies such as NEM would be replaced by, at best, compensation for excess energy exported at the wholesale rate.  Never mind that SCE is charging you anywhere from 19¢ to 40¢, you are only going to be compensated at the 2-6¢ rate!

Much of the “logic” behind the petition argument will be familiar to readers of this blog: rooftop solar is economically inefficient, NEM distorts wholesale energy markets, and imposes unfair burdens on ratepayers without solar.  Nevermind that all of these points have been debunked before (their expert calls those debunking efforts “irrelevant"), what is important to note is that while many of us are locked out and hunkered down during this crisis, are opponents are not.  They are hard at work, hiring top-dollar DC lawyers to press the case while the rest of us are just trying to get through the month.

Make no mistake about it - if this petition is successful, it will be the end of NEM as we know it, and not just in New England, but nationwide!

This is where organizations like CALSSA(for solar installers here in CA) and the Solar Rights Alliance (for solar system owners) are so critical.  If you are a solar installer, or run a solar company and you are not a CALSSA member, shame on you.  Join!  If you have a solar installation on your roof and you don’t belong to the Solar Rights Alliance - wake up!  Join!

NERA’s petition was filed on April 14th and under the fast track rules that NERA requested (and paid a $30,000 filing fee to secure), comments are due by mid-May.   We will update you when we learn more about its progress.  Watch this space.

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Jim Jenal is the Founder & CEO of Run on Sun, Pasadena's premier installer and integrator of top-of-the-line solar power installations.
Run on Sun also offers solar consulting services, working with consumers, utilities, and municipalities to help them make solar power affordable and reliable.

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