Category: "PWP"


  10:32:58 am, by Jim Jenal - Founder & CEO   , 1230 words  
Categories: All About Solar Power, Solar Economics, Utilities, PWP, SCE

What You Need to Know About Commercial Solar Power in Three Easy Lessons - Part 1: Understanding Your Bill

While many companies sit on the sidelines with accumulated capital, we have argued before that spending some of that capital on a commercial solar power system makes great economic sense.  But for some companies (and their facility managers and accountants and Board Members, and so on), commercial solar is still a mysterious concept, filled with confusing jargon and competing claims.  Can a commercial solar power system really be as economically beneficial as the proponents (like this blog) claim?

Rather than answer that question directly (well, ok, the answer is YES but please read on), we thought it would be useful to actually layout the case for commercial solar power in some detail.  Although no blog post (or series of blog posts) can take the place of a face-to-face conversation that takes into consideration all of the relevant  elements of a specific company’s situation, there are enough common elements that can and should be explained to demystify the overall process.  That is the task of this series - to teach you, the business/building owner everything you need to know in preparation for installing a commercial solar power system on your building.

First things first - before you ever even call a solar power company - and we will explain how to find the good ones in Part 3 - you need to start with something more mundane: your electric bill.  When was the last time that you really looked at your electric bill?  For many business or building owners the answer is never.  Oh sure, you certainly know how much you are paying - but do you know why you are paying so much?  What horrors are hiding in your bills?

The Shocking Facts Hiding in Your Electric Bill

The Basics - Usage & Demand

There is probably a very good reason why neither you, nor anyone else at your company has ever looked closely at your electric bill - it is terribly confusing.  Let’s start with some basics.  Almost every commercial user pays for at least two major components on their electric bill: usage and demand.

Usage is the more familiar component as it is the basis for your residential electric bill.  It is based on the total amount of energy that you used over the course of the billing cycle (usually one month for commercial customers).  Usage is measured in total kilowatt hours (kWh). Usage charges are based on some specific cost per kWh which is defined in the rate schedule that applies to your utility account (more on rate schedules in a minute).

Demand is a bit more complicated - it is usually defined as the greatest amount of power that the utility has to provide to you over a measured period of time during the billing cycle.  For SCE customers, demand is the peak power required during any 15 minute period over the month.  That means that if your building has multiple HVAC units and they all come online during the same 15-minute window, your demand will spike much higher than it would if those units came on in a staggered fashion (since the power demand of an HVAC unit is highest when the compressors are running as they will be when the unit is first started.)  Demand charges are billed per kilowatt (kW) of power.

Rate Schedules

Every utility has a variety of rate schedules that might apply to a commercial building and you could pay vastly different amounts - that is to say you could save a lot of money - by switching to the most economical rate schedule for which you qualify.

GS-2 rate structure model
SCE’s GS-2 Rate Schedule Model (click for larger)

Case in point - SCE has two rate structures that commonly apply to small to medium size commercial buildings: GS-1 and GS-2.  (For those ready to get into the details, here is a link to the GS-1 rate schedule and here is a link to the GS-2 rate schedule.)  The beauty of the GS-1 rate schedule is that it has no demand component.  But here’s the catch - your peak demand must not exceed 20 kW in any three of the past twelve months.

We had one potential customer who was paying under GS-2.  When we analyzed their bills - the first step in preparing a proposal for installing a commercial solar power system - it was apparent to us that based on their bills, they were entitled to actually be billed under GS-1.  When we met with their facilities manager to discuss our proposal, we pointed out that they could have saved over $2,000 the past year if they had been on the right rate schedule and we encouraged them to contact SCE about getting switched to GS-1.  (No, SCE had not suggested that to them.)  Strangely, none of the other solar companies that they had talked to had explained that to them, yet once they called SCE, they were switched over immediately.  (Oh, and they hired us to handle their commercial solar installation!)

Here’s another example.  PWP generally has low rates, but their mid-level commercial rate schedule (M-1)  has one of the most significant “gotchas” we have seen anywhere - and we are yet to speak to a single customer who was aware of this before we pointed it out.  The M-1 rate structure includes a demand component (labeled “distribution"), but unlike SCE’s demand component described above, PWP charges you for the peak demand in any 15-minute window for the past 12 months! That means that if on one unlucky day, everything in your building comes online all at once during the same 15 minutes, not only will you pay for that peak demand that month, you will pay for that peak demand for every month for the next year (unless a higher demand comes along to take its place)!  For one of our customers, they had a peak demand one month that spiked at 82 kW, yet their average for the next 12 months was only 36 kW.  Under the M-1 rate schedule, they paid $5,300 more than they would have if they only paid for their monthly peak demand.

Models Matter

At Run on Sun we have devoted a lot of time to mastering the intricacies of the various rate schedules used by the utilities in our service area.  We have turned that understanding into a series of rate schedule models that allow us to accurately model your prior utilities bills and then make accurate predictions regarding your potential savings from a host of measures - changing rate schedules, reducing your usage or peak demand, or installing a solar power system. Some companies simply assign a fixed amount of savings per kWh that their proposed solar power system will produce and call that your potential savings.  Such an approach ignores the complexities of how your electric bill is actually calculated and can mask other steps that you could take to save money.

We firmly believe that energy efficiency is way more cost effective than energy generation and we will share with you our ideas and observations on how you can save money long before you throw the switch of (or even sign the contract for) your commercial solar power system.  So before you pick up the phone, pick up your electric bills and check out what is hiding there - it is the first step in getting the greatest value from your commercial solar power system.

Up Next: Part 2 of Our Series - Understanding Solar Rebates and Tax Incentives as they apply to a Commercial Solar Power System.

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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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