Category: Performance

  • We're NOT net positive in 2019! What happened?

    Year summary: We used 8,062 kWh and generated 7,945 kWh for a net of -117 kWh for the year.

    Note: I’m 6 months behind in finishing this update. Back dating the post to January 4 when I statrted it.

    Last year we had relatively normal usage and rather low solar production. This year we have slightly less than normal solar, but higher usage. The end result is our second net overage in the lifetime of the house.

    Chart showing solar and usage values for last 8 years
    Chart showing solar and usage values for last 8 years

    We produced 5% less solar than average, and used 14% more than average. That tipped the scales once again, just enough to push us into the negative zone. On the long view however, we’ve still generated a surplus of 9,040 kWh over the last 8 years since the house was built.

    We were performing fairly normally until September. Let’s break down the numbers.

    Read more...
  • First quarter 2019 performance

    Q1 2019 summary: 6% colder, 14% more usage and 16% more sun as compared to Q1 2018.

    We recorded a low of -11.8 on January 22, far from our lowest recorded temperature of -17.3°F on February 14, 2016. Our high was 69.5, lower than the 77.6°F last year. In 2012 we recorded a high of 82.4°F in the same period.

    Overall, here’s how this quarter compared to 2018.

    Q1 Comparison 2018-2019
    Q1 Comparison 2018-2019
    Read more...
  • We're NOT net positive in 2018! What happened?

    Year summary: We used 7,356 kWh and generated 7,256 kWh for a net of -100 kWh for the year.

    2018 is the first year we have not generated a solar surplus. In short, we produced 15% less solar than average, and used 5% more than average. That tipped the scales just enough to break our 6 year net zero running streak. On the long view however, we’ve  generated a surplus of 9,157 kWh over the last 7 years since the house was built.

    Chart showing solar and usage values for last 7 years
    Chart showing solar and usage values for last 7 years

    We were performing fairly normally until Q4. Let’s break down the numbers.

    Read more...
  • Third quarter 2018 performance

    Q3 2018 summary: 33% warmer, 1% more usage and 7% less sun as compared to Q3 2017.

    Nothing exciting to report, which is normal for 3rd quarters.

    At 7am on July 15th we became net positive for the year. As of the end of September, we have a surplus of 1,115 kWh heading into the final months of 2018. That’s about 211 less kWhs than last year at this time. Overall for the year, our solar production is down about 7%.

    Overall, here’s how this quarter compared to 2017.

    Chart showing usage, solar, net and hdd
    Chart showing usage, solar, net and hdd
    Read more...
  • Second quarter 2018 performance

    Q2 2018 summary: 18% colder, 2% less usage and 4% more sun as compared to Q2 2017.

    Overall, here’s how this quarter compared to 2017.

    Q2 Comparison 2017-2018
    Q2 Comparison 2017-2018
    Read more...
  • First quarter 2018 performance

    Q1 2018 summary: 4% colder, 3% less usage and 13% less sun as compared to Q1 2017.

    I said it last year and I’ll say it again, it was a whacky winter. Lots of cold days, but also lots of warm days. It would be warm for a week or two, the ground would thaw, then we’d get snow.

    We recorded a low of -17.1 on January 7, close to our lowest recorded temperature of -17.3°F on February 14, 2016. Our high was 77.6, higher than the 73.6°F last year. In 2012 we recorded a high of 82.4°F in the same period.

    Overall, here’s how this quarter compared to 2017.

    Q1 Comparison 2017-2018
    Q1 Comparison 2017-2018
    Read more...
  • We're net positive again in 2017!

    We used 7,198 kWh and generated 7,966 kWh for a net of 769 kWh for the year.

    2016 was our second highest net energy surplus year after 2012 and our highest solar generation year.

    2017 was our second lowest net energy surplus year after 2014 and our lowest solar generation year over the last 6 years. We had a lot of cloudy days and snow covered panels.

    Q4 2017 summary: 2% colder, 7% more usage and 5% more sun as compared to Q4 2016.

    In Q4 our total usage was 2,022 kWh, a 7% increase from our 1,890 kWh in 2016. We also generated 65 kWh more solar.

    Overall, here’s how this quarter and the year compare.

    Charts comparing Q4 and YOY usage, solar and HDD
    Charts comparing Q4 and YOY usage, solar and HDD
    Read more...
  • Third quarter 2017 performance

    Q3 2017 summary: 33% cooler, 9% more usage and 7% less sun as compared to Q3 2016.

    Nothing exciting to report, which is normal for 3rd quarters.

    At 1pm on July 17th we became net positive for the year. As of the end of September, we have a surplus of 1,326 kWh heading into the final months of 2017. That’s about 574 less kWhs than last year at this time. Overall for the year, our solar production is down about 13%.

    Overall, here’s how this quarter compared to 2016.

    Chart showing usage, solar, net and hdd
    Chart showing usage, solar, net and hdd
    Read more...
  • Second quarter 2017 performance

    Q2 2017 summary: 15% warmer, 1% less usage and 15% less sun (412 kWh) as compared to Q2 2016.

    Overall, here’s how this quarter compared to 2016.

    Chart showing usage, solar, net and hdd
    Chart showing usage, solar, net and hdd
    Read more...
  • First quarter 2017 performance

    Q1 2017 summary: 3% colder, 6% more usage and 20% less sun as compared to Q1 2016.

    I’ll say it, it was a whacky winter. Lots of cold days, but also lots of warm days. It would be warm for a week or two, the ground would thaw, then we’d get snow.

    We recorded a low of 3.3, quite a bit warmer than the -17.3°F  last year’s low. Our high was 73.6, less than the 78.5°F last year. In 2012  we recorded a high of 82.4°F in the same period.

    Overall, here’s how this quarter compared to 2016.

    Q1 Comparison
    Q1 Comparison
    Read more...
  • We're net positive again in 2016!

    We used 6,837 kWh and generated 8,910 kWh for a net of 2,073 kWh for the year.

    This is our second highest net energy surplus year after 2012 and our highest solar generation year.

    Q4 2016 summary: 24% colder, 38% more usage and 17% less sun as compared to Q4 2015.

    In Q4 our total usage was 1,890 kWh, a 38% increase from our 1,368 kWh in 2015. We also generated 281 kWh less solar.

    Overall, here’s how this quarter and the year compare.

    Charts comparing Q4 and YOY usage, solar and HDD
    Charts comparing Q4 and YOY usage, solar and HDD
    Read more...
  • Third quarter 2016 performance

    Q3 2016 summary: 10% cooler, 3% less usage and about the same amount of sun as compared to Q3 2015.

    Nothing exciting to report, which is normal for 3rd quarters.

    At 7am on May 31st we became net positive for the year. As of the end of September, we have a surplus of 1,900 kWh heading into the final months of 2016.

    Overall, here’s how this quarter compared to 2015.

    Chart showing usage, solar, net and hdd
    Chart showing usage, solar, net and hdd
    Read more...
  • Second quarter 2016 performance

    Q2 2016 summary: 23% cooler, 8% less usage and 11kWh more sun as compared to Q2 2015.

    Overall, here’s how this quarter compared to 2015.

    Chart showing usage, solar, net and hdd
    Chart showing usage, solar, net and hdd
    Read more...
  • First quarter 2016 performance

    Q1 2016 summary: 26% warmer, 21% less usage and 33% more sun as compared to Q1 2015.

    Although it seemed a lot warmer this winter, 1,023 less heating degree days than Q1 2015, it was still 9% cooler than first quarter 2012 which is the warmest winter since we began recording temperature data.

    Despite it being warmer this winter, we recorded a low of -17.3°F, 1.2 degrees colder than last year’s low. Our high was 78.5°F which was considerably warmer than last year’s high of 52.8, but lower than 2012 when we recorded a high of 82.4°F.

    Overall, here’s how this quarter compared to 2015.

    Chart showing usage, solar, net and hdd for Q1 2016
    Chart showing usage, solar, net and hdd for Q1 2016
    Read more...
  • We're net positive again in 2015!

    We used 7,141 kWh and generated 8,694 kWh for a net of 1,552 kWh for the year. This is our second highest net energy year after 2012. Here’s our progress for the first 4 years in the house.

    All values in kWh (except HDD which is base 65°F).
    Usage Solar PV Net usage or (surplus) Avg. daily usage HDD
    Total 28,056 34,473 (6,417) 19.1 26,530
    2012 5,601 8,856 (3,256) 15.3 5,885
    2013 7,206 8,575 (1,368) 19.7 6,810
    2014 8,108 8,348 (240) 22.2 7,063
    2015 7,141 8,694 (1,552) 19.6 6,772
    Read more...
  • Third quarter 2015 performance

    Q3 2015 summary: 38% warmer, 22% less usage and 3% more sun as compared to Q3 2014.

    Traditionally, 3rd quarters are pretty boring in the home performance category. No heating. Generally no air conditioning. No ventilator because the windows are open. At this time of year, the main job of the house is to keep the rain out, and we didn’t get much of that this quarter.

    Our most exciting finding this quarter was that we had a 1+ megawatt month. In August we produced 1.003 MW. This is only the second time we’ve produced more than a megawatt in a single month. The first was August 2012 when we produced 1.018 MW.

    Sometime in early August we became net positive for the year. We now have a surplus of 1,239 kWh heading into the final months of 2015.

    Overall, here’s how this quarter compared to 2014.

    Charts comparing Q3 usage, solar and HDD
    Charts comparing Q3 usage, solar and HDD
    Read more...
  • Second quarter 2015 performance

    Q2 2015 summary: 4% cooler, 17% less usage and 2kWh more sun as compared to Q2 2014.

    It is a wet, foggy and cold July 4th at Up Hill House. Perfect weather to update our quarterly numbers! And like today, this quarter was fairly uneventful. In energy terms, however, that is not a bad thing for us.

    Overall, here’s how this quarter compared to 2014.

    Charts comparing Q2 usage, solar and HDD
    Charts comparing Q2 usage, solar and HDD
    Read more...
  • First quarter 2015 performance

    Q1 2015 summary: 7% cooler, 2% more usage and 14% less sun as compared to Q1 2014.

    Although it seemed a lot colder this winter, it was really only 7% cooler than first quarter 2014. And considering there were many nights much colder than last year, -16°F versus -8°F last year, we only used 2% more energy. The biggest difference was snow cover, specifically the snow that covered our solar panels. This resulted in 14% less energy generated this quarter compared to last year, which means we netted out using 21% more energy from the power company.

    Overall, here’s how this quarter compared to 2014.

    Chart showing usage, solar, net and hdd for Q1 2015
    Chart showing usage, solar, net and hdd for Q1 2015
    Read more...
  • We're net positive again in 2014!

    We used 8,108 kWh and generated 8,348 kWh for a net of 240 kWh for the year. The combination of cold temperatures, less sun and the plug-in Prius brought us close to our net point. Here’s our progress for our first 3 years in the house.

    All values in kWh (except HDD which is base 65°F).
    Usage Solar PV Net usage or (surplus) Avg. daily usage HDD
    Total 20,914 25,779 (4,864) 19.1 19,758
    2012 5,601 8,856 (3,256) 15.3 5,885
    2013 7,206 8,575 (1,368) 19.7 6,810
    2014 8,101 8,348 (240) 22.2 7,063
    Read more...
  • Detailed data finally available again

    We changed energy monitors in March and the new data format broke my database scripts, but I finally found time to update my scripts and publish* our hourly data for the period March to November. One thing I noticed immediately was that I had been sloppy in my reporting of energy use for that time period. I used the UI to select dates and didn’t realize I wasn’t getting the most accurate timeframe. As a result, I’m going to post an updated energy record at the end of January for the entire year.

    Read more...
  • 3rd quarter 2014

    Since we’re coming up on the solar tour this weekend, I wanted to post the numbers for July through September.

    Read more...
  • July energy snapshot

    2013-2014 comparison of energy break even points
    2013-2014 comparison of energy break even points
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  • Energy snapshot - first 6 months of 2014

    I’ve been slacking on the energy updates. I love my new energy monitor, but it broke my database update scripts and I haven’t had time to fix them. In the mean time I thought I’d share some high level updates.

    1. Transition from eMonitor to eGauge data begins March 8. Missing data for about 4 hours.
    2014 Usage Solar PV Net usage or (surplus) Avg. daily usage HDD
    Total 4,983 4,318 665 27.5 6,583
    Jan 1103 472 631 35.6 1,380
    Feb 994 511 483 35.5 1,174
    Mar 1 1060 743 317 34.2 1,170
    Apr 751 889 (138) 25.0 550
    May 662 834 (171) 21.4 231
    Jun 413 869 (456) 13.8 64
    Read more...
  • January performance snapshot

    Living in a super-insulated house, I get very excited when extreme cold weather arrives. It is the only way to see how well the house performs in low temperatures. This January was the coldest month that we’ve lived in the house.

    Read more...
  • Fourth quarter 2013 performance

    Q4 2013 summary: 10% cooler, 22% more usage and 10% more sun as compared to Q4 2012.

    In Q4 last year our total usage was 1,599 kWh. This year is was 1,957 kWh, a 22% increase. Despite snow covering the collectors for a few days and cloudy weather, we still produced 10% more energy in Q4.

    Overall, here’s how this quarter and the year compare to 2012.

    Read more...
  • We're net positive for 2013!

    Pie chart of energy usage by circuit 2013
    Pie chart of energy usage by circuit 2013
    Stacked bar chart of energy usage by month 2013
    Stacked bar chart of energy usage by month 2013
    Chart of monthly temperature ranges 2013
    Chart of monthly temperature ranges 2013
    Chart of temperature buckets with ASHP usage overlay 2013
    Chart of temperature buckets with ASHP usage overlay 2013
    Chart of water usage 2013
    Chart of water usage 2013
    Read more...
  • Our NESEA Zero Net Energy Building Award Submission

    Presentation Board
    Presentation Board

    We submitted our entry materials for the NESEA Zero Net Energy Building Award yesterday. We didn’t quite have a full year’s worth of data for last year’s competition. So we were excited to apply this year. You can find out more about the requirements for the competition on the NESEA site.

    Read more...
  • Third quarter 2013 performance

    Q3 2013 summary: 36% cooler, 38% more usage and 2% less sun as compared to Q3 2012.

    In Q3 last year our total usage was 927 kWh. This year is was 1,283 kWh, a 38% increase. Although it feels like it had rained a lot more this year then last, we only produced 2% less energy in Q3.

    Overall, here’s how this quarter and the first three quarters compare to 2012.

    Q1-3 comparison
    Q1-3 comparison
    Read more...
  • Second solar anniversary

    Last month marked our second solar year. We produced 8,519 kWh and used 6,410 kWh for a net of -2,110 kWh from June 2012 to June 2013.

    Read more...
  • Second quarter 2013 performance

    Q2 2013 summary: 13% colder, 44% more usage and 4% less sun.

    In Q2 last year our total usage was 1,021 kWh. This year is was 1,468 kWh, a 44% increase. Although it feels like it had rained a lot more this year then last, we only produced 4% less energy in Q2.

    Overall, here’s how the first and second quarters compare to 2012.

    Q1 and Q2 comparison
    Q1 and Q2 comparison
    Read more...
  • 72% of our usage is grid supplied, even though we produced more than we used!

    Supply Mix
    Supply Mix

    In the last year (April 1, 2012 to March 31, 2013), we used 6,046 kWh of electricity and produced 8,576 kWh for a net surplus of 2,530 kWh. That’s awesome right?

    Read more...
  • Estimating heat energy for 2012 - Revised

    Now that we have January - March 2013 circuit-level usage values, I thought I’d go back and revisit my original 2012 heat estimate using a different method.

    Read more...
  • First quarter 2013 performance

    Q1 2013 summary: 20% more cold, 22% more usage and 15% less sun.

    See April 7 Update at end of post.

    In Q1 last year our net usage was 228 kWh. This year is was 953 kWh, a 300% increase! In March 2012 we actually generated a surplus, but not this year.

    Overall, here’s how the first quarter compares to 2012.

    q1-comparison
    q1-comparison
    Read more...
  • 335 days and 6 slices of data

    Composite heatmap, generation, usage, ashp, dishwasher, hdd
    Composite heatmap, generation, usage, ashp, dishwasher, hdd
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  • Estimating heat energy for 2012

    April 7 Update: Using a different method I estimated  that we used 903 kWh for heat energy in 2012, that’s 16% of our total energy use. That would have cost us about $117 (using $0.13 per kWh).

    We don’t have a full 12 months of data for our heat, but using heating degree days (HDD) and performance thus far we can estimate that we used 591 kWh (+/-20%) for heat in 2012. That’s 11% of our total energy use for the year.

    Here’s the math…

    Read more...
  • We're net positive for 2012!

    Pie chart showing circuit usage YTD
    Pie chart showing circuit usage YTD
    Bar chart showing circuit usage per month
    Bar chart showing circuit usage per month

    Year Summary

    We’re net positive for 2012! We used 5,601 kWh and generated 8,856 kWh for a net surplus of 3,256 kWh. We used an average of 15.3 kWh per day.

    Read more...
  • Home Performance App Upgrade

    I’ve updated our home performance app at, NetPlusDesign.com.

    Screenshot from new app.
    Screenshot from new app.

    At the beginning of the year I put together a simple online tool that displays our energy and temperature data on a daily and hourly basis. It gave me an easier way to track and visualize our energy usage on a month to month basis without a bunch of spreadsheet work. The heat maps provide an easy way to quickly find days of high energy use and see what else was going on that day. This helps me understand why usage might be high on a particular day.

    Read more...
  • November performance

    Chart showing monthly usage, generation, net and hdd
    Chart showing monthly usage, generation, net and hdd

    We used 498 kWh and generated 615 kWh for a net surplus of 117 kWh in November. This is our ninth consecutive surplus month. We’ve generated a surplus of 3,622 kWh so far this year, guaranteeing we’ll be net positive for our first year of operation.

    Read more...
  • Temperature and energy use observations

    As I continue sifting through our performance data, I’ve been focusing lately on outdoor temperatures and their relationship with our heating and cooling energy use. These are a few of my observations.

    70 percent of time period was below 68 degrees
    70 percent of time period was below 68 degrees

    We have 9 months, 274 days, 6,576 hours of temperature data, from February 1 to October 31. Of those 6,576 hours, 4,635 outdoor temperature hours were below 68 degrees F.  Roughly 70% of the recorded time period has been below 68 degrees F.

    Read more...
  • Correlating HDD with heating energy use

    Chart showing poor correlation between HDD and heat energy use
    Chart showing poor correlation between HDD and heat energy use

    I spent a few of the Sandy storm days indoors and decided to indulge my inner nerd. I’ve been tracking all our house performance data using monthly spreadsheets, which can make it difficult to filter data or look for trends across months. So I downloaded mySQL and imported all our energy and temperature data into the database. This is the first in a series of posts on what I find as I sift through the data.

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  • October performance

    Total usage vs production in kWh as of Oct 31
    Total usage vs production in kWh as of Oct 31

    October was overshadowed by the events of the last week. Despite the best efforts of Hurricane Sandy we are safe and dry at Up Hill House. We had plenty of strong wind gusts, but not nearly as bad as the costal regions. We were prepared for the worst. We stocked up on water and easy to prepare meals. We have a small propane burner that can be used to heat water or simple cooking. We packed the chest freezer with ice. We filled the bathtub for flushing and the cistern was full for the farm critters. Thankfully the power never went out.

    Read more...
  • September performance

    performance chart september
    performance chart september

    Fall weather arrived last month. More rain and clouds with cooler nights. We generated 883 kWh in September, down 15% from last month, but still about 37 kWh better than predicted. We generated on average 29.4 kWh per day.

    We used 292 kWh, our lowest month yet. That’s down 7% from the previous month. We used the air conditioning only 2 days and heating for 1 day. We used 9.5 kWh for cooling / dehumidification, and 5.9 kWh for heating. Together that’s 5% of our month’s total usage. We generated a 591 kWh surplus this month, our 7th surplus month in a row.

    I changed the format of the table a bit. Months now run down the table instead of across.

    Read more...
  • August performance

    We generated 1,018 kWh in August, up 5% from last month. That is our best month yet, and our best daily average of 32.8 kWh per day as compared to the last two month’s average of 31.3 kWh per day. Typically solar generation starts to decline in August, with decreasing sunlight hours, more clouds and more heat, but not this year.

    Read more...
  • Net metering update

    Back in our June performance update, we mentioned that June was our first year anniversary for our solar PV system. In New York, the utility keeps track of the amount of power we use and generate (net-metering) over the course of a year and on the anniversary date credits the owner with any surplus power generated. We generated a surplus of 3,650 kWh from June 1, 2011 to June 1, 2012.

    After several calls to customer service and waiting 75 days, we finally got our credit from the power company.

    Are you sitting down? /joke/

    $159.68

    Read more...
  • Our water usage

    Water usage to date
    Water usage to date

    In our July performance post I stated that we were tracking our water usage and water pump usage to calculate the efficiency of the pump. Dan Gibson asked in a comment about our water usage, so I thought I’d cover that here. He says in his comment that there are not a lot of actual hard numbers on water usage and he’s definitely right. Most estimates I’ve seen online say 50 to 100 gallons per person, which seems both excessive and vague at the same time.

    We installed water meters on the main line and the inlet to the hot water tank. We have usage data starting in January when we moved in.

    Read more...
  • July performance

    Heat map of high temps in July
    Heat map of high temps in July

    We generated 970 kWh in July, up 3% from last month. That is our best month yet, but in line with last month’s daily average of 31.3 kWh. We used 319 kWh, 5% less per day on average than last month. We turned on the air conditioning for 3 days during a particularly humid run, and periodically for a few days the next week. We used 12 kWh for cooling / dehumidification, 8% of our month’s total usage. We generated a 651 kWh surplus this month, our 5th surplus month in a row and highest yet.

    Read more...
  • June performance

    June seemed to be in line with past year averages at least temperature-wise. (1 heating degree day less than the 10 year average, 52% less HDD than May, 8% more sun). We turned on the air conditioning for a couple of hours on three particularly hot and humid days. We’ve also started building a barn this month so that is starting to show up in our energy usage. This partially resulted in 5% higher energy usage in June. We used 0.36 kWh for space heating and 2.76 kWh for cooling. Our daily average usage was up 9% from May. We generated a 614 kWh surplus this month, our forth surplus month in a row and highest yet.

    Read more...
  • May performance

    May was a warm and rainy month. (52% less heating degree days than April, 7% less sun). This partially resulted in 20% lower energy usage in May. We only used 4.8 kWh for space heating. Our daily average usage was down 23% from April. We generated a 558 kWh surplus this month, our third surplus month in a row.

    Read more...
  • April performance

    circuit usage pie chart
    circuit usage pie chart

    April saw the return of weather normalcy. (12% less heating degree days than March but only 8% less than the 10 year average, 7% more sun). This partially resulted in 25% lower energy usage in April. We used 49 kWh just for space heating. We also installed a clothes line outside and used the clothes dryer less this month. Our daily average usage was down 22% from March. We generated a 538 kWh surplus in April, our second surplus month in a row.

    Read more...
  • Cruise control for the home

    Drivers and pilots make use of technologies that make their life easier and increase energy savings, why not home owners?

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  • March performance

    Actual vs. Projected for 2012
    Actual vs. Projected for 2012

    March madness, the weather that is. March was freakishly warm and much sunnier than February (33% less heating degree days, 31% more sun). This partially resulted in 23% lower energy usage in March. Our daily average usage was down 28% from February. We generated a 345 kWh surplus in March, the first since we moved in Jan 1st.

    Read more...
  • Visualizing home performance data

    Seeing a month of home performance data isn’t easy. If you’re looking for patterns it’s like looking for a needle in a haystack.

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  • Our new wireless energy monitor

    We were excited to see our new eMonitor 4 from Powerhouse Dynamics arrive Wednesday. We purchased it through EnergyCircle. Sage, the rep at EnergyCircle, said it would ship first thing in the week and he wasn’t kidding. For more info see our previous post, Power monitoring – lessons learned.

    The installation was very easy. The setup had a few kinks.

    Read more...
  • Power monitoring - lessons learned

    In January we purchased a TED5000 (The Energy Detective, 5000 series) to more accurately monitor our power usage and generation over the year. We had some intermittent problems getting it to work dependably. Eventually we were able to get it stabilized after adding an inline noise filter. Noise in this case is signal noise which can be caused by any electrical gadget plugged into a socket. All seemed well for a while and we got a great month’s worth of data for February. Then strangely TED stopped working shortly after exporting the February data, and we didn’t notice it till yesterday. Now we’ve lost 7 days of data and it still isn’t working.

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  • February performance and fun with charts

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  • January performance

    Performance for our first month in the house. Updated Feb 5.

    1 504 net usage + 369 generated = 873 kWh of total energy consumed. I goofed up earlier because I forgot the utility meter reading is a net value, not a supply value. Originally I subtracted the two values and got into a mess. Thanks Walter for spotting my error. This should be easier now that I have TED up and running.
    Jan 1, 2012 Feb 1, 2012
    Utility Meter NET 97,095 kWh 97,599 kWh
    Solar PV meter 5,054 kWh 5,423 kWh
    Solar PV generation 369 kWh --
    Monthly usage 873 kWh 1 --
    Net usage or (generation) 504 kWh --
    Read more...
  • Charting Temperatures

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  • It's official, we earned our 5+ Energy Star rating. But the result was not what we expected.

    Our contractor used our house as an opportunity to apply for status as an Energy Star builder. It worked. He’s now an Energy Star approved builder, and we have a 5+ star Energy Star home. In the process we discovered a big difference in the projected energy usage by our Energy Star certified rater using REM/Rate and our certified PassivHaus consultants who used the PassivHaus spreadsheet.

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  • House performance tracking

    This is the first post in the performance tracking category . I plan to add more sophisticated tracking devices in the future, but for the moment I’m simply tracking our monthly power meter and solar generation meter readings, as well as our total water usage.

    Our readings at the beginning of January:

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