Wednesday, October 24, 2012

September update

Well, I am still a month behind.  October is nearly over and I am just getting time to write up how things went in September.  My total bill for September was $152, with usage at 1,023 KWh.  Solar generation was 754 KWh.  Last year, for the same total energy usage, my bill would have been $443.  So, a savings of $291.  Of course, had I had the medical allowance and the TOU billing, my bill would have been only $214, leaving a $62 savings for the solar alone, but that is an unfair comparison.  My effective rate from PG&E wasjust 14.9 cents per KWh.  When I add in the free solar, it lowers the effective rate per KWh to just 8.5 cents per KWh.  My effective rates per KWh last year were over 30 cents per KWh.

As for total solar generation last month, it was just 689.67 vs an expected generation of 735 KWh.  Total generation is now almost 1000 KWh under what was projected.

Wednesday, September 26, 2012

August update

When I first started tracking my solar production, I was looking multiple times a day at how the panels were doing.  This was back in March.  Now, I check once a month or so.  Not sure if that is because I am so busy at work, or because the newness has worn off.

Anyway, the numbers for August are in (and have been for a few weeks).  I finally got around to seeing how I did.  My bill from PG&E was $205 for the month.  Total usage was 1330 KWh, with an additional 814.92 KWh coming from the panels.  Had I not had the solar panels, my cost would have been $562.  Even with the medical allowance, it would only have gone down to $410.  So, my savings for the month were significant, over $350 for the month.

However, according to the projections, my generation was supposed to be 863 KWh.  I am still about 10% below the production target for the year.  We will see how this trend continues.  So far, April was the only month I was close to the target production, and I have never met, let alone exceeded the target.

Monday, August 20, 2012

July update, better late than never

I have been trying to get around to posting my July update for almost a month now, and never seemed to have the time to do it.  I finally decided it had to be done, or I would have to do the August update at the same time!

My power usage was the highest it has been, by far, since I have had the solar panels installed.  Total usage from PG&E was 1166KWh, with solar generation being another 789.9 KWh.  A lot of this had to do with the weather, as it has been over 100 degrees here most of the summer.  In addition, my youngest daughter managed to break her arm, resulting in her being in a cast for 4 weeks, and not being able to be very active, resulting in a lot of home time for the family.

With the usage being so high, my costs skyrocketed.  PG&E charged $194.80 for the month.  The good news is that had I used the same amount of power last year, my cost would have been $508!  So, while my costs were pretty high this month, they are much lower than they would have been.

The monthly total solar generation for July was 810.6 KWh, vs an expected 921 (the expected values were adjusted downwards recently).  For the year so far, the estimates are about 10% higher than the actual.  Hopefully, it gets made up in the back half of the year!

Tuesday, July 17, 2012

Why I went Solar

    I have been asked a few times why I decided to go solar.  I am not someone that has ever been considered an environmentalist.  I leave that to my sister.  However, I can say this decision was all about green.  As in money.
     A few years ago, we moved from Folsom, CA to Cameron Park, CA.  A distance of about 12 miles.  In Folsom, we had natural gas for heat, the clothes dryer, the stove, and the hot water heater.  In Cameron Park, we are 100% electric.  In Folsom, electricity was provided by SMUD, in Cameron park it is PG&E.  I never knew what a difference it makes.  Our combined gas and electric bills in Folsom rarely exceeded $200 a month, and were often half that.  My first power bill in Cameron Park exceeded $600.  Talk about sticker shock.
     We did what we could to reduce the electric bill.  I replaced the 15 year old AC unit with a brand new one.  I was promised 20% savings on electricity the first year.  It was more like 5%.  Not good enough.  Electricity prices kept increasing, and my monthly bill remained way too high.  I kept hearing ads for solar on the radio promising savings, but I didn't think it was real.
      I called a few companies, and had them come give the sales pitch to us.  I did the math, and the payback periods for buying the system were long.  I am an engineer, I put the data in spreadsheets, I ran projections.  Even with the government incentives, the numbers didn't pencil out.  I dropped it for a few years.   More ads came along, promising new pricing models.  I took a look again.
      This time, the numbers came out closer.  I could achieve $60-$70 a month in savings with no upfront costs.  This was better, but would require me to commit to a long term contract.  Another company came in, and the numbers were similar.  I was on the fence.  Then, Real Goods came back with a new promotion.  I could get the same pricing they had offered before, but the first year would be free.  Now, instead of saving $60-$70 a month, I would be saving over $200 a month the first year.  I finally pulled the trigger.
      Results so far have been in line with expectations.  One thing I learned is that PG&E net billing method calls for me to pay only some of the taxes each month, resulting in a bill of about $12.  At the end of a year (I assume after my February bill), PG&E will send a bill for the net cost of what I used.  This essentially means they are providing me with a free loan.  Another side benefit.
      The key thing I have found is to take a look at all the data the salesmen throw at you, and make sure to do your own analysis.  Your savings can vary quite a bit depending on the plan you pick and how much you invest.  Sometimes, investing a little more actually lowers your savings quite a bit.  Always run the numbers, and figure out where your break even point is.

Monday, July 2, 2012

June Update

Since I was on vacation for the past week, I didn't have a chance to post about the totals from my June bill and so I will combine that with the June actual vs expected.

To start with the simple one, June generation was 786.56 KWh, while expected was 938.  While there was only 1 day of low generation in June, the higher temperatures apparently lower the efficiency of the panels, so I never had a day above 28.5 KWh generated, and had only 1 day below 23 KWh (in fact, it was only 2 days under 25 KWh, with the second lowest day coming in just over 23 KWh).  So far, the total generated is up to 2865 KWh, while the expected was 3317.  When I called Real Goods last month to ask about this, they said the expected was too high and they would work with the web guys to get that fixed, but so far, it is unchanged.  According to my contract, the estimated generation from year 1 is 7545 KWh, while the guaranteed total is 7168 KWh.  There is no breakdown by month in the contract, so I don't know if I am on track or not.  I am 4 months in, and at roughly 40% of the guaranteed number (and 38% of the estimated number).

Now for the more interesting part.  I once again used negative peak power (-18 KWh).  But, I used more part peak and offpeak power than last month (a total of 521 KWh vs 353 KWh), probably due to the increased temperature.  My total PG&E bill was $49.56 this month.  If I had used the same amount of power last year, the bill would have been $287.43.  The medical exception alone would have reduced that to  $176.20.  With solar, the medical exception doesn't even kick in, since I stayed below the baseline.  Solar this month saved me $237.87.  So, it is right in line with the $90-$100 dollar savings I expected to have if I had to pay for solar ($141 a month next year, since the first year is free!).

Monday, June 4, 2012

Real Goods makes good

I posted about all the issues I had prior to getting solar system installed.  I have talked with several customer service reps and managers at Real Goods, going over the problems, and all apologized and told me it would be corrected.  I few weeks ago, I received a call from Ben, who is an operations Manager at Real goods.  He once again apologized, and offered me a "virtual installation".  I had never heard of the that, but he explained that they would pretend my system got installed on the original date, and send me a check for the amount I would have saved on my PG&E bill for the delays.  It sounded great.  I am not sure how they calculated the amount, but when they came up with $600, I decided not to dig any deeper.  It took a few weeks, but on Saturday, the check arrived.  So, now my net cost for the system is no longer $0, it has gone down to -$600!

Friday, June 1, 2012

May totals are in

Well, the May totals are in, and it looks like there may be an issue. According to the Generated vs Expected chart, I was supposed to hit 930 KWh of solar generation in May.  However, the total generation was only 831 KWh.  I don't think the weather was a major factor, as there were only 2 days of sub-par generation.  On May 3rd, the system only generated around 11 KWh, and on May 26th, it was 16.5 KWh.  Otherwise, no day in the month yielded less than 22KWh or more than 31 KWh.  May 5th was when the system peaked at just over 30 KWh for the day.  The system is designed for 5.6 KWh max, and it looks like the most I am ever seeing is 4.5 KWh instantaneous power.  I called my contact at Real Goods, to ask about why it is generating less than expected, and it looks like they will need to send someone out to check the system out and see what is going on.  I'll see what they find.

Thursday, May 24, 2012

How low can it go?

Well, my latest PG&E bill hit my inbox this morning.  Since this bill covers the period when we switched from winter rates to summer, I was waiting to see how that impacted my results.  It looks like the results were very favorable.  The weather for the last 31 days has been pretty clear, and not too hot so that helped a lot.

The first 10 days of the latest bill covered the end of April, so it was still under winter rates.  For those 10 days, I used only 15 KWh at part peak, and 153 KWh at off peak.  Solar generation was 283.44 KWh, so my total utilization was just about 45 KWh a day.  The cost for this was a whopping $17.36.  A savings of $48 due to solar.

The final 21 days of the bill were at the summer rates.  The main difference in summer rates is that the day is now broken into 3 rate periods, with the addition of peak.  Peak rates are ridiculously high.  And part peak rates are not much better.  During the winter, the difference between part peak and off peak rates is less than 2 cents a KWh.  For the summer, part peak is nearly 2x off peak rates, and peak is 3x off peak.

This actually turned out to be a good thing for me.  The panels actually generated 18 MORE peak KWh of power then I used.  So, PG&E gave me a credit of just over $5 for this.  I only used 33 KWh of part peak power, and 320 KWh of off peak.  My total cost for the 21 days of summer power was only $31.90, for a total bill of $49.

Without solar, the total would have been just over $250, so savings were just over $200.   The medical allowance was much less a factor this month, as it saved me just a few pennies.  If I didn't have solar, it would have saved me about $60.  Time of use pricing also ended up saving me about $12.  It will be interesting to see what happens when it gets hotter, as I don't think my peak usage will continue to be negative.

Tuesday, May 15, 2012

Calculating savings

Now that I am a couple of months in, I am finding that PG&E does not make it easy to calculate the savings from.  I started trying to calculate savings using a simple spreadsheet, and found that it wasn't simple enough.  I then decided to write a quick program in C to do it for me.  It took only about an hour to have something that was usable and accurate.  Then I tried to share it with a few friends.  Microsoft apparently doesn't make it easy to just share a program, you need to pack up various pieces to make it work.  This got me to thinking there had to be a better way.  So, I started poking around, and found that it was possible to do it as a webpage.  Unfortunately, making a webpage to do the calculations involved learning Javascript, which was a bit frustrating.  After a few days, I managed to get a slightly less featured program to work.  It doesn't allow for easily modifying the rates, but I can add that eventually if I need it.  Otherwise, it has the functionality of the program I wrote in C.  In fact, it has the same basic algorithm.  I just wish I knew of a better way to debug javascript.  Not being a compiled language, I didn't have a compiler to help spot typo's, which was very annoying.  Anyway, I have it done, and if you are interested in trying it out, click here to give it a try.  I would appreciate any feedback or questions.

Tuesday, May 1, 2012

April Data

Since April is now in the books, it is time to look back at how the solar system fared vs what was projected.  Total generation for April was 744 KWh.  The finance company projections show that expected generation was 794 KWh.  So, 50 KWh short of expected.  This is 100 KWh closer to expected then March, but still short.  Projections for May are 930 KWh.  We will see how it goes.

Wednesday, April 25, 2012


Month 2 results are in.  My April PG&E bill arrived in my inbox today.  And boy, is it a shocker.  My total bill for the last 30 days was $98.81.  This is the lowest bill I have ever received from PG&E.  Not all of the savings was due to solar, the wonderful weather we had helped quite a bit.  Without solar, my bill for this past month would have been $181 or so, by my calculations.  So, solar saved me $82 and change.  However, had my 1 year of free solar been up, I would have had to pay $140 for the solar power, resulting in a net loss for the solar of $58.

That is only telling part of the story though.  In pulling the numbers together for last months analysis, I found out that PG&E offered a medical equipment baseline allowance.  Since my wife uses a CPAP machine for her sleep apnea, we were able to qualify for that.  This increased my baseline allowance from 28.6 KWh per day to 35 KWh per day.  This saved my an additional $1.32 on my bill, after the solar.  But, if I didn't have solar, the medical allowance would have saved me $84.92.  Too bad I didn't know about this 4 years ago when we first got the CPAP machine!

Without the medical allowance, and without solar, my total bill would have been $265.94.  My savings would have been $165.81.  Even after paying for the solar, this would have left a $25.81 savings.  The chart below shows my projections of what the costs would have been in the various scenarios.

Solar Med Cost Overall Savings Solar Savings
Y Y $98.81 $167.13 $82.21
Y N $100.13 $165.81  
N Y $181.02 $84.92  
N N $265.94    

Sunday, April 1, 2012

March summary

In Cameron Park, we didn't have much of a winter to speak of. Until I got my solar panels installed, that is. Of the 31 days in March, I had 6 days with terrible (<5 KWh) generation, 4 days with bad (<10 KWh) generation, and 11 days with excellent (>25 KWh production), and 2 days of good (>20 KWh) production. The remaining 8 days were somewhere between 10 and 20 KWh. That left me with total generation of 503.4 KWh in March. This is significantly lower than the 655 KWh that the website shows me is the estimated production for the system. Hopefully, April is better for me!

Wednesday, March 28, 2012

TOU impact

I decided to do one more check. When they switched my meter, they switched me to TOU (time of use) pricing, rather than the fixed pricing I was on before. Turns out, this was a big help. I saved an additional $35 on this plan over what I would have saved had I stuck to the fixed pricing.

First bill

I received my first PG&E bill since installing the solar this week. Unfortunately, PG&E assumes when you go to solar, you don't want to do any analysis, so they send you a simplified bill. The bill didn't have the details I was looking for in order to see what my savings are. I called up the solar customer service at PG&E (the normal customer service is no longer able to help me) and found that the information I wanted was on page 4 of the bill, and they normal only send pages 1 and 2. They were able to flag my account to receive the detail bill from now on though.

Now that I have the full bill, I am able to see that I used 1389 KWh of power from PG&E for the 27 days that the bill covered. My solar system generated just over 547 KWh of power for the same period, putting total usage at 1936 KWh. Unfortunately, on March 1, PG&E changed rates further complicating the cost analysis, but with some help from Excel, I was able to do some calculations.

First, the big positive is that I stayed in the Tier 3 pricing, using less than 200% of baseline. This kept me from paying for the highest cost power. Without the solar, I would have been well into Tier 4 pricing. Each KWh in Tier 4 is 4 cents more than in Tier 3 (and Tier 3 is more than double Tier 2 pricing, adding 15 cents per KWh to the price). In order to calculate my savings, I added the solar generation to the appropriate tiers. My Tier 4 usage alone would have cost ~$128, but solar was able to completely eliminate that. I was able to reduce Tier 3 usage by another ~$45, putting the total savings for the month at $173.

These numbers are approximate, since I am unable to figure out how much of the power I used from solar was used during the partial peak prices (1-7pm weekdays) vs off-peak (all other times). PG&E allocates baselines based on % of power used at each of the rate periods (I used about 10% of my power during the partial peak period, so my baseline quantity for partial peak pricing was 2.86 KWh a day, rather than the 7 KWh a day it would have been had they done it based on % of the day spent in each rate category). Therefore, I made the assumption that all of the solar would have been used during the more expensive Partial Peak time-frame, rather than the cheaper off peak. This means my saving estimate is probably a little high, but the best I could do.

I did run the numbers, and found that the way PG&E does the allocation of the baseline actually works out in my favor this month, since I would not have used enough power to hit the full Tier 2 limits had the allocation been done on a percentage of time basis, so I would have had more Tier 3 usage in off-peak. The savings was right around $5.

Bottom line, the solar system saved me from paying PG&E around $173 this month, and cost my $0, since my first year of solar power is free. If I was paying for the solar power, it would have cost around $120, putting my net savings this month at $53.

Tuesday, March 6, 2012

The first 11 days

I can now track the performance of my solar system from my desk. It is surprising how often I have found myself checking to see how it was doing. Since I sit in a cube with no view of the windows at work, I can now tell what the weather is without standing up just by seeing how much power I am generating at the time.

Of the first 11 days I have had the system, it has been relatively sunny 9 of those days. We did have 2 days of rain last week, and I was surprised that I still was generating power on those days (although significantly less than on sunny days. In the first 11 complete days, the system generated 211.6 KWh of power, an average of over 19 KWh a day. That jumps to 22.5 KWh a day when the 2 rainy days were excluded.

My typical consumption last month was around 70 KWh a day. Baseline for my zone in PG&E land is 28.6 KWh a day during the winter months. So, the solar system is not dropping me all the way down to Tier 2 (up to 130% of baseline), but it does get me down below the cutoff for tier 3 (200% of baseline). Of course, right now I am really only generating power between 7:30am and around 4:30pm. In a few months, I should get a good 2 more hours of generation time, which would give me another 10-12 KWh of power a day.

I can't calculate the savings until I get my first PG&E bill, but this is the first time I can say I am looking forward to seeing a bill.

Friday, February 24, 2012

On the grid

I received an e-mail on 2/14 from PG&E confirming that they had received all the required paperwork from Real Goods. When I had talked to them a few weeks ago, they had said it would take from 10-30 business days from when they received the paperwork until they could come to the house and swap the meters.

I guess they were wrong. Yesterday, I happened to be working from home for an unrelated reason. The doorbell rang, and I was shocked that it was PG&E! They were here to install the meter. It took all of 30 minutes, about 2 minutes of which was time with the power to the house off. I was in the middle of a meeting while this happened, so I had to switch to our backup wired phone (yep, still have one of those in the house), and then it was done. When the meeting ended around 4:30, I was able to see the paperwork the tech had left. I now am switched to E-6 Time of Use net energy metering. When I went out to look at the shiny new meter, there was a couple of things that stood out.

First, it has a sticker on it that says "Meter runs both directions". That is what I have been waiting for. The second thing was a tag attached to the meter with a label that explicitly grants me permission from PG&E to turn on the solar panels and hook them to the grid. So, I reached up to the inverter box and turned the dial to ON. I was rewarded a few seconds later with a green light. Unfortunately, it was nearly 5pm by this time, so there wasn't much light left to generate power, but I am officially generating power.

I was hoping to be able to check how much power I was generating, but I am still waiting for the information from Real Goods on how to do this remotely. I will check the readout on the inverter box itself when I get home tonight, but in the near future, I should be able to do this from my computer.

So, if you had 2/23/12 as the day my solar would be working, you win the prize. Now to see how much power it generates, and what my savings are. Stay tuned.

Wednesday, February 1, 2012

Another delay

Since the county signed off on the permit, I thought the system was ready to start working. All that was left was for PG&E to swap out the meter on my house for one that could run backwards, and to connect the 2 systems. I was told that PG&E typically takes 3-4 weeks to do this. So, after waiting 2 weeks and hearing nothing from PG&E, I decided to give them a call to see when the connection would happen. That is when I got my next surprise. PG&E never received the request from the solar company to do the connection. Once they do, they have 30 business days to do the hook up, but their goal is 10 days.

So, my next phone call was to Real Goods Solar to find out what the hold up was in getting the paperwork to PG&E. I know all the paperwork PG&E required was ready, since the helpful agent at PG&E had pointed me to a list on their website, and I had received a packet from Real Goods that had my copies of all the documents. Apparently, the finance company that Real Goods used for my transaction hadn't signed off on it yet. I am not sure why this is a holdup, as PG&E doesn't require anything from the finance company to do the hookup. The agent at Real Goods said it was in process and should be taken care of this week. I sure hope so, since the system is doing nothing sitting on my roof not hooked up to the meter.

What upsets me the most is that once again there was no communication from them on an issue. The last contact I had from them was the day of the inspection, when the rep said all he had to do was go back to the office and send the paperwork in to PG&E, and then it was all in their hands to get it turned on. Obviously, that wasn't true. And two weeks later, i is still not true. If I had not called to find out when the next step would happen, I would not even be aware of the issue.

I guess we will see if the paper work gets to PG&E next week.

Thursday, January 19, 2012

Inspection completed

The next step in getting the solar system operational was completed today. The county came and signed off on the final inspection. It was a bit anti-climatic, as the inspector was at the house for all of 10 minutes. Real Good Solar sent a rep out to the house to meet with the inspector and make sure everything was good. I feel a bit sorry for him, since he had to drive 3 hours each way for something that took 10 minutes. Although, he did hook up the internet monitoring to the system while he was at the house. Unfortunately, the system is not using WiFi to connect to my internet access point. Instead, it uses some other wireless technology to transmit to a receiver that then is plugged in through an Ethernet connection to my router. This wireless receiver needs to be plugged in to the wall as well. Should I subtract out the power needed for this from what the system generates?

Monday, January 9, 2012

A little more drama

Today, the install of my new solar system started. However, it almost didn't happen. On Friday, I received an e-mail from the sales rep at Real Goods solar asking me to call him. I thought it was just a reminder about the Monday install. No such luck.
Apparently, the shade readings that I was told were a resolved problem, were not resolved. Rather than the 95% sun the contract specified, my roof would only be getting 90% sun. This means that the panels will generate about 8% less electricity then planned. The sales rep said that he had been too aggressive trying to get me a good price. The next question I had was what does this mean to me.
The short answer is that the panels would now only save me $60-$70 a month, rather than the $90-$100 I had expected. My monthly payment for the panels would stay the same, but since they generate less electricity, the effective rate for the power would go from 22.7 cents a KWh to about 28 cents a KWh. Needless to say, I wasn't happy. I felt that the new numbers were not advantageous enough to me to justify going solar.
The salesman offered several other options, none of which were acceptable to me. I let him know I was not happy. Letting me know of an issue the business day before the install for the second time was not acceptable. Especially since I was told the issue was resolved 2 weeks ago, and I had heard nothing from them since.
Two hours later (it was now almost 3pm on Friday), I got a call from the sales manager. He asked for an opportunity to fix it. About an hour later, he told me he had gotten approval to lower the price of the system to where I was now paying 23 cents a KWh. The system would still produce 8% less then before, but now I would pay less per month in order to maintain the price per KWh at close to what it was supposed to be.
I agreed, with the proviso that I wanted the install to go ahead on Monday. I had already made plans to handle my meetings on the phone from home, and didn't want to change plans at the last minute. He agreed, and had the new pages of the contract e-mailed to me so I could sign them and e-mail them back over the weekend.
Today, at around 10:30, the installers showed up. They installed the brackets that will hold the panels and the inverter. Tomorrow, they are supposed to finish. The installers will be back at around 9:30 in the morning (they are coming from about 3 hours away, so I guess I can't complain about the late start).