Monitoring Improvements

 

Our solar system has been producing now for over 7 months.  Right from the start, I kept a close eye on the data that was generated from the installed system.  Data is originating from two sources:  (1) solar production is monitored and recorded via the Solaredge Inverter and monitoring application, and (2) the household energy consumption detail is monitored from a stand-alone device (Sense) installed within the electrical panel in our home.  Both sets of information can be viewed via computer or mobile phone.

Early on, I knew that I wanted a unified data stream in one monitoring application.  Recently, I  installed an Energy Meter connecting the solar inverter and the household power lines.  Current transformers are used to sense energy Consumption by looping the main power lines to the house.  As a result, the Solaredge Inverter Monitoring application now provides a total picture of all relevant energy flows:

    - Solar Production

    - Energy Imported from the Grid

    - Energy Exported to the Grid

    - Self-Consumed Energy from Solar Production (as it is generated from the solar system)

    - Total Energy Consumed = Energy Imported + Self-Consumed Energy from Solar

A few screen captures of the monitoring system information shown below should help convey the data.

The Original Monitoring

This image shows the solar System Production on August 29, 2020.  The total energy production for the 24 hours of the day was 66.59 kWh.  The monitoring information only included the solar production.

The Updated Monitoring System

This screen capture shows the monitoring of all variables: System Production (a combination of both Self-Consumption and Export) and Consumption (a combination of Self-consumption and Import).  September 11, 2020 was a very cloudy and rainy day with small solar production (only 9.61 kWh of energy.  The Consumption (shown in red) normally averages around 1-2.5 kW, but peaked at 5 PM on this day, due to the electric oven use.  All but a very small amount of the solar energy was self-consumed (shown in blue).  A small amount of exported energy (shown in green), only 0.91 kWh occurred at times when solar production was in excess of consumption.  This energy was exported to the ComEd grid.

This last screen capture shows the monitoring on September 15, 2020 on a relatively sunny day.  Total System Production was 65.34 kWh.  25% of this was Self-consumed, and 75% of this was exported to the grid.  For the day, our home consumed a total of 77.23 kWh of energy, of which only 16.53 kWh was supplied by the solar system.  The normal 1-2.5 kW consumption was significantly higher between midnight and 4 AM because we were charging our Tesla electric car during this time.

 

  

It should be noted that the last screen capture shows the interplay between solar production energy and consumption.  Obviously, solar production only occurs during daylight hours.  But consumption occurs throughout the whole day.

Our home is part of the ComEd Hourly Rate Pricing Program.  This means that energy we import or export is priced at a varying hourly rate.  In the picture above, the price during the Midnight to 4 AM time ranged from 0.8 - 1.3 Cents/ kWh (energy demand is lower for ComEd and they charge less for the hourly energy).  Between the solar production time period, the hourly price was 1.4 - 1.9 cents/ kWh (more demand means that ComEd typically charges more per hour for the energy they supply).

But this means that I am buying energy at a lower price and exporting (selling back to ComEd) at a higher per hour price.  It works out nicely!

Major Milestones

August 2, 2020

Milestones along a path mark accomplishments that are worth observing and celebrating.  The original incentives for 'going solar' were both idealistic and economic.  How can I contribute to the environmental welfare of our planet?  Can solar be both financially viable and environmentally positive?

August 2020 marked the accomplishments of solar production on our system that were noteworthy.

Milestone 1 - A Monthly Production High - As July rolled over into August, the installed solar system reflected the continued month-over-month increase that one may expect.  I speculate that July's peak solar production of 2.012 MWh  (2,012,000 Watt-hour) of energy will be the maximum monthly level  for the calendar year.  The production is directly dependent on the weather conditions, and time is not on my side for a higher peak in this year.  The daily available sun time has been diminishing since Late June - the days are getting shorter. 

The bar-graph above plots by month the 2020 solar production level.  January (01) reflects only 66% of the month in operation.  And August (08) is only partially complete at the time this graph was developed.

Milestone 2 - A System Production Level Total Achievement - There is always something pleasing about reaching certain numerical levels.  Reaching 1.0 MWh (1,000,000 Watt-hour) of lifetime production occurred late in February 2020.  It would take another six months to reach the next order of magnitude level, 10 MWh.  This did occur on August, 4, 2020.  As a point of reference, 10 MWh is about equivalent to the amount of electricity used by about 3,330 homes during one hour.

There were no bells or fireworks after reaching this level, just silent satisfaction.  My monitoring system also provides an estimate of pounds of CO2 emission saved at 15,500 pounds, which is equivalent to roughly 117 trees planted.  Nice.

Milestone 3 - Electric Bill Reductions - The original design of the solar production system predicted an approximate solar production output at 81%  of 'historical' electric usage.  Past electric bills were used as the planning electric consumption base.  Estimating solar production is complicated by weather, panel shading and solar panel efficiencies, plus many other factors.  The electric consumption of our home is also dependent on weather, devices used and lifestyle preferences.  I expected my ComEd (supplier of electricity) electric bill to be lower by a respectable amount, but predicting the level is extremely complicated.

But our milestone achievement has been especially pleasing.  For the last two billing periods (June and July), our actual bill has been $0.  In fact, there has been a credit that has rolled over monthly.  It was a combination of replacing incandescent lights and positive solar output.  This will not continue I am certain, as solar production reduces later in the year, but it is satisfying today.

Other News - And the last bit of news, while not a milestone regarding our system, is the continuing growth of solar in our subdivision.  As of August, we now have 4 homes producing solar energy.  Last November there were 0 homes.  This is still only 3.6% of the total subdivision home count, but it is a positive direction.

Thanks. 

Snow Drops

4/21/2020

April weather in the Chicago-land area is difficult to forecast.  It can be clear with bright blue skies, or dark-clouded and cold with snow flurries.  Or heavy rains with lightening and thunder.  Pick your favorite.

So it has been an interesting solar production month so far.  Every day seems to bring another production record for my installed system.

But the event that I really did not expect was the somewhat startling thump that occurred on two peaceful mornings.  Our morning ritual is to wake up, look out the bedroom window for any unusual stirrings in the neighborhood.  After throwing water on the face, walk down the stairs to the first floor and make coffee.  Sit down with my brew and open up the news.  My dining chair faces the sliding window overlooking our deck, bird feeders and the backyard detention ponds.  It could be pre-dawn or the sun may be up (pretty casual these days).

After recent snowfalls on two days in mid-April, I expected the solar production to be reduced.  That is until the snow melts from the panels.





This is the view on the morning of April 15,2020 after getting approximately 5-6' overnight.




















This is the view on the morning of April 17, 2020 after getting about 4" overnight.

At about 7:45 AM on the 15th and then again on the 17th, we were surprised by the snow drop from overhead.  The picture below shows the remnants of the snow that slid off the roof.

There is no warning of the imminent drop.  But there are 30 feet of glassy panels that are rising along the roof slope up to the peak above the sliding glass door.

If you get enough sun load on the snow, the slippery glass panel surface becomes a great slide.  I have not viewed the avalanche build up on the roof, but it generates enough momentum to shift the snow clean.

And then there is plenty of great panel area to generate energy.





















As I mentioned earlier, April seems to be a good solar month.

Since the beginning of the month, five separate 'largest ever' days of solar production occurred.  Progressively higher 'highs' occurred on April 2, 10, 16, 18 and 20.  And right now, April 21st looks like another high.

Since we are using only about 28-35 KWh of energy a day, I decided to use the excess solar energy today to 'fill up' the electric vehicle during the day.  An EV charge usually is limited to 10 KW and normally requires about 2-4 hours of time (which I would normally do during the night time).

Sunny days are great!

April 2020 Milestone

4/11/2020

As of 5 PM today, we are 21 days into the Illinois "stay at home order".  Our community lifestyle has dramatically changed over thes last 3 weeks.  Because of the order, our buying, traveling and social habits have been minimized to only the essentials.  When I do venture out, the road traffic is minimal.  I have been able to take my neighborhood walks, but social distancing is practiced by almost every one I "meet".  Clearly, life today is different and won't revert to normal for some time.

But, the grass is green and it continues to grow.  The trees have started to bud.  Our Cornelian Cherry Dogwood has blossomed with yellow flowers.  The pollen count is high.  And the sun is rising earlier every day and races to a higher zenith.

The sun part is great for the solar system that was installed in the latter part of December last year.

At this time, my daily ritual is to mentally note where the sun is rising and then check the solar production monitoring application.  Several checks during the day are standard.

April 2020 has brought several different milestones.

Milestone #1 is surpassing 3 MWh of total energy produced, reached in earlier April.

Milestone #2 is achieving the highest level of daily solar energy production, thusfar, at 76.83 KWh produced on April 10, 2020.

 

The chart to the right is taken from the monitoring application display.  It shows centrally the System Production (76.83 KWh), and it also shows the line graph of the Kw energy produced by the solar panel against time.

The granularity of the plot is 15 minute segments.  It shows that the first energy received by the system was in the 6:15 AM segment and was a mere 0.024 KW.  The last bit of energy received was at 7:15 PM and was 0.022 KW.  Peak energy was received at 9:00 AM, 11:30 AM and 1:30 PM, and is limited to 10 KW.

The more abrupt growth of the curve and more gradual downward slope of the curve is a function of the panel and roof position and the path and height of the sun.





Another milestone occurred March 20, 2020 when I received my first ComEd (local power company) billing with a full month of solar production.  It was great to see that the prior billing period reflected a flow of 790 KWh of energy "from the grid", and a flow of 957 KWh of energy TO the grid.  My monitoring system does not yet tell me how much self-generated energy (solar) that I consumed at home, but some simple math can tell me this.

[For Billing Period 2/192020 - 3/19/2020]

Solar Energy produced                               = 1285 KWh
Solar energy pushed to the ComEd Grid =   957 KWh

Solar energy self-consumed                     =   328 KWh
ComEd additional energy required         =   790 KWh
Total Energy required                                = 1118 KWh

So, you may ask, Why do you need to acquire energy from ComEd if your solar system produced more than you required in the billing period?
The answer is that the sun is up only during the day making solar energy.  My consumption is 24 hours a day.  And on some of those billing days, I charged my electric cars in the middle of the night.

Please keep safe and healthy my friends.  Everyone is so dependent on each other to lessen the impact of the Covid-19 pandemic.  As long as the sun continues to shine, we will make it to the other side of this panemic.  I am anxious to see you all then.

A Milestone...

2/21/2020

It's amazing how a sunny day today seems so much more appreciated than it did in the past.  Don't get me wrong, sunny days are always desired, but now it means more.

This week our month-old solar network reached a milestone.  Two milestones in fact.

Date: 2/21/2020
Daily Production:  65.546 KWh  (Milestone #1 = Highest Daily Production)
Lifetime Energy: 1.03 MWh  (Milestone#2 = Surpassing 1 Mega Watt hour Production)

I noted that on that occasion, the solar system had generated the equivalent of 40 trees being planted, or 1588 lbs. of CO2 Emissions Saved.  All for a greener earth!

The differences in energy production is quite noticeable in the above daily bar chart. The three 65 KWh days between the 19-22 dates reflect close-to-the-maximum available power for those days, given the length of the day.  I'm anxious to see my first real ComEd bill which will reflect the Net-Metering aspect of the solar set up.  This is the mechanism to allow both self-consumption of solar energy, as well as pushing solar energy back into the ComEd grid.  I'll have a blog posting to discuss this later.

We've been enjoying more sun.  The days are getting longer and solar energy production is increasing. More power to the sun!

Early January Production

January 22, 2020

Basking in the beautiful, warm sunshine of January in the Northwest suburbs of Chicago is not something that most people can ever recall.  Unless you are an avid "outdoors" person, anxious for the chance to attack the ski slopes, or you have recently installed a photo-voltaic solar array on your roof.

I guess I fall into the latter category.

I now anxiously await sunrise, gauging just how much sun will be out during the day.  Also, I'm checking the Weatherbug application for the local hourly forecast.  I must believe that the newness of the solar production system will wear off in time.  But, the geek in me loves to monitor the solar production and think about my energy meter running in reverse.

So here are a few glimpses of the solar installation and the first few days of solar production.

Roof perspective of South-facing roof with racking

Roof perspective of East-facing roof with racking & Power Optimizers attached

The South side of the East-facing roof

Photos of the final solar panel installation.

The North side of the East-facing roof

The South-facing roof panels

The first weeks production is shown below excerpted from the SolarEdge monitoring application.

The production level is graphed on a daily basis beginning January 16, 2020.  Each day's production begins at sunrise and stops at sunset.  The jagged look of the day's production reflects the amount of sun hitting the solar panel.  Cloudy days are shown as low peaks and multi-peaked plots.  Only half of January 22 is shown.

January 21 was the largest production day, coming in at just over 51 kWh of energy.  As a reference, our actual consumption of energy on January 21 was just under 30 kWh, so this was a push-it-into-the-grid day!

Nice to see the sun.  It has a different meaning these days...

Receiving Photons...

January 6, 2020

Monday, 12:20 PM - the SolarEdge Inverter power is initiated.  I was advised that ComEd had given the approval to start the system and connect to the grid.

Flipping the inverter "on" switch  and turning the safety switch dial seemed anti-climactic after all of the research, negotiating and waiting that went into the birth of the solar array system that now sits on our roof.

 And yet, the effort is still not complete.  But it is now producing energy... I think.

SolarEdge Inverter

Faith told me that the sun that was pouring down on the roof was being converted into electrical energy.  But I had no way to validate this until the monitoring site could be initiated.  Our SolarEdge Inverter was the newer model which did not have LED read-out on the front panel.  To see the solar energy production, I needed to download an app which still needed to be configured for my installation.  This monitoring configuration was to be set up by the selling company, and required about 24-48 hours.  But I was impatient.

After 24 hours (why should it take longer than this, I reasoned), I contacted the inverter company directly.  They provided me a "view only" set-up mode application which showed my kWh production since it was activated.

Image from Set-Up Application

I was pleased to see that from 12:20 PM on Monday to 9:30 AM on Wednesday, the system had generated 57.26 kWh of energy.

Monday had been a relatively sunny day, but Tuesday had been cloudy.  And the Winter skies in Palatine Illinois are notoriously dark and the sun visibility is short.  Days were getting longer, but we had a long way to go.














A call to the Selling company Project Manager was made to expedite the configuration.




About 12:30 PM I was informed that the configuration had been completed.  I could access the SolarEdge Monitoring application to more explicitly monitor the Solar array output.
 Yahoo!

It was enjoyable watching the monitoring information.  The satisfaction that the effort was actually providing a positive benefit was appreciated.

The monitor information below shows several key elements:

The Energy Today = 19.18 kWh reflected about 50% of the days sun.
The Current Power = 389.92 W reflects the solar array output at around 4 PM (sunset at this time is around 4:40 PM).
The Lifetime Energy = 87.2 kWh refelects energy produced since Monday's turn-on.

 One can see the green line plot that shows the declining solar energy production available during the Winter afternoon.  Monitoring started just before 12 noon.

The monitoring app provides an abundance of data for the geek that I am.  I can see the individual PV module output at any time.  And output data can be viewed for multiple time periods.





The PV module array is shown at the end of the day in a physical view.  The residual module output is shown on the picture, as well as the module numerical reference.





















For those of you that may be seeking more details, here is a little bit of definition to baseline our understanding: 

- photon--A particle of light that acts as an individual unit of energy.  Our sun friends...
- PV--Abbreviation for photovoltaic(s).
- photovoltaic (PV) cell--The smallest semiconductor element within a PV module to perform the immediate conversion of light into electrical energy (dc voltage and current).
- photovoltaic (PV) array--An interconnected system of PV modules that function as a single electricity-producing unit.  The modules were installed on the roof.
- inverters--Devices that convert dc electricity into ac electricity (single or multiphase), either for stand-alone systems (not connected to the grid) or for utility-interactive systems.
- watt (W)--The unit of electric power, or amount of work (J), done in a unit of time. One ampere of current flowing at a potential of one volt produces one watt of power.
- kilowatt (kW)--1000 watts.
- kilowatt-hour (kWh)--One thousand watts acting over a period of 1 hour. The kWh is a unit of energy.

When you (if you) look at you electric bill  you may see the monthly consumption of electrical supply to your home. This is usually stated in kWh (kilowatt-hours).  This is the energy that powers your lights, toaster and electric ovens.  For most homes the monthly consumption of kWh may be 500 -1300 kWh, depending on your home's efficiency.  You pay for the supply of this energy and an assortment of additional fees for distribution, metering, equipment, taxes and many other miscellaneous charges. 

So, it's installed and finally functioning.  For a 2.5 day period in the dead of Winter in Palatine Illinois, we produced about 87.2 kWh of power.  I would guess that we consumed about 100 kWh of energy.  The output was a bit higher than originally expected.  Good news.

But Winter is harsh here and I can expect many cloudy days, with small solar generation.  But it is still a step forward.  The monitoring system says that the solar generation produced is equivalent to 3.4 trees planted!

More coming as I learn the details of the system.