Stand-alone Solar Applications

The sun charges us up in more ways than we can count. It is, of course, the mood enhancer when we wake up to a sunny day.

When most people think of solar energy, though, they think of panels on the roof, generating electricity for all their household needs. This is a great option, but it is the most expensive option, kind of like investing in a car for all your mobility needs.

If you only need to go to the corner store, there are more affordable options of getting there, like walking or biking. It’s the same with solar; not everyone may need a rooftop system big enough to power all the household’s needs. A more task-oriented stand-alone system could well fit the bill.

A local bike shop has installed 3 ceiling fans powered by 2 panels set up as awnings over their front door, needed exactly when they’re busiest – sunny days! Read about the fan & panel installation and afterward.

Finding the alleyway too dark to approach the garage doors at night, one local household installed solar floodlights. These can soak up the sun during the day, and automatically come on when sensing motion after dark. Easier wiring, one time cost without adding to the electric bill – what’s not to like?

Before you head out to the stores, here’s a review of solar flood lights.

Most of us need a desk lamp only in the evenings. This could be another perfect application – a solar desk lamp, good for several hours into the evening.

Our Friends at Germantown Monthly Meeting manage a local community garden, the Old Tennis Court Farm. 

At this garden, you’ll find panels on their shed roof, providing electricity for a well pump that fills up water barrels for use by gardeners. Over time, they’ve added an inverter offering an AC power source to the garden. And invested in an electric lawnmower and weed whacker that could be recharged and available for use by all gardeners.

Search for “solar charger” and you’ll find an array of products designed to charge cell phones and other USB devices, AA and AAA batteries, even laptops and refrigerators. For those looking to light up a detached garage or shed, and maybe a power tool, one of Goalzero’s Yeti models with a lead acid battery, packaged as a kit with solar panels could be just the ticket. It can also be used instead of a generator for emergencies.

Another family in our neighborhood managed to run their “media room” on sunlight pouring through the windows. They kept all all the components inside, simplifying the wiring. With components from Harbor Freight, a 100W panel charging a 12v 35a battery suffices to run the TV, computer and sound system well into the night. All for under $500.

So think of your electricity needs. We’d love to hear what dedicated uses you’ve come up with for sun-charged electricity. Share your project story with us at nwphlsolar [at] gmail.com, and have a sun-charged day!

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After a rough start, I now love our rooftop PV system

It’s been over 3 months since our rooftop system has been hooked up to net metering. I remember the day, October 31st, 2017 when our utility (PECO), replaced our old meter with one that could read the flow of electrons in both directions.

The installers got the panels onto our roof in early August. But to get the generation from our panels interconnected with the grid took some time. This was critical, because we wanted net metering – credit for excess generation that was fed back to the grid.

Why the 3 month delay? The power line to and from our house could have high voltage, said our utility. Meaning sending homegrown electrons out to the grid could be unsafe. The recommendation? Join a pilot program to use an inverter that would limit the voltage we’d push onto the line.
We jumped on this suggestion. But, the initial settings caused the inverter to turn off when voltage hit 253 Volts for just one second, taking 5 minutes to come back on. This happened so often (663 times in a 2-week period, for a total of 55 hours of lost generation) that I began dreading sunny days due to system shutdown. In fact, our system appeared to work better on cloudy days.
To share my frustration visually, take a look at the 2 charts below showing solar production throughout the day. The one on the left is our system; the one on the right is a neighbor’s, on the same day. Our system kept shutting down, right at mid-day, wiping out the beautiful green hump of solar generation that the neighbors saw.

It took a few phone calls with both PECO and our installer, and a re-reading of the PUC regulations, to discover that a setting change (power down the system only after a full minute of high voltage, instead of one second) could resolve this. That made all the difference. Now I’m in love with sunny days and my chart looks more like my neighbor’s.

Our system has been running nicely since mid-November, about 3 winter months. From that date through the end of February,  we generated 1,604 kWh of solar electricity. Our household used 512 kWh of that before it went to the grid, and we imported 1,068 kWh from PECO, mostly at night, for a net export to PECO of 24 kWh. Agreed, this is a tiny amount, but this was over the winter! Given that generation is expected to be much higher in other seasons, this should allow us to gradually replace gas appliances to electric, and eventually charge an electric car.

How big is our system? A total of 29 panels, 12 on the roof facing southeast, and 17 on the rear southwest roof, at a few different angles on an 1880’s Victorian with steep roofs. We selected 335 Watt panels, for a total system size of 9,715 Watts (9.7 kW). Curious what this looks like? Take a look at the time lapse photography of the installation.

Whatever became of our 1st buying group from February?

Having recruited a dozen households for rooftop solar in February, the first installation began in early March. Seven months later, we have ten completed installations enjoying electricity from the sun.

The last two installs were in late August and early September.

Our eleventh household had some challenges with PECO’s transformer supplying their house. This has caused a major delay, but they are now waiting on PECO to do some work and should be able to move forward soon.

The first install, completed in late April, has produced seven megawatt hours of electricity so far! The homegrown electricity not only runs their household, it also charges the family car, a Nissan Leaf, while pushing the surplus generation back onto the electrical grid. Their monthly electric bill has dropped to $8.45, the minimum to maintain an account with PECO.

If you like charts, you’ll love the one below about this same household. Yellow is daytime electric use; blue is nighttime electric use. Columns are the 23 months before their installation went live, and the few months after. You’ll notice the expected seasonal variation, but see what happens after April. At night, they still get electricity from the grid. But their monthly average usage is negative, and has been for the six months so far. They are thrilled with their decision.

Pushing electricity onto the grid has many steps: Make the decision, Sign the contract, Obtain interconnection go-ahead from PECO, Obtain permit from the City, Order the solar panels & components, Install the system,
Coordinate City inspection, Coordinate meter replacement by PECO, Register for SRECS (Solar Renewable Energy Certificates). Remember if you are considering solar, you only need to do the first two steps. The installer takes care of the rest!

Below is the chart showing all the steps, completed and not, for each household in our first round. The steps are down the side, and the number of households is along the bottom. Soon, this chart will be all green!

Electricity for the house. From Renewables, please!

You understand all the reasons to switch to renewables: the climate pickle we’ve got ourselves into, and the resultant unbreathable air from burning fossil fuels like coal, oil and gas to generate our electricity.

You also understand the need for a rapid transition to renewable energy, particularly in the electricity sector. But… you may live in an apartment, a condo, or just a house with a shady roof — all of which made it impossible to invest in solar panels on your own roof. Or, though your roof gets tons of sun, you may not have the funds to invest in rooftop solar.

What do do?

  • We suggest you switch your electricity supplier to The Energy Co-op, choosing their EcoChoice 100 product.
  • We also suggest you join us: The Northwest Philly Solar Co-op for a $25 annual fee. We offer tips like this, and also one-on-one energy efficiency help. 

Why?

The Energy Co-op is a local, well established company, spun off from Weavers Way Co-op. Their EcoChoice 100 product offers 100% renewable electricity, 99% from PA wind farms and 1% from solar. With a fixed rate, you won’t get surprised 6 months from now! Other companies may offer cheaper options, but most promote renewables in other states, and all appear gimmicky to us. Don’t take my word for it. Read Marion & Dave Brown’s experience; then read Chrys Brown’s experience, both shared in the Weavers Way Shuttle. Then, buy local!

How?

Go to The Energy Co-op’s website.. Or call their only office, in Center City Philadelphia, where someone from their small staff will assist you with the switch. Their number is 215.413.2122. Tell them Meenal sent you!

Now to get my own mother to switch back to The Energy Co-op after someone came to her door and presented a gimmick…

Rooftop solar and your PECO bill

This post will explore the PECO power bill, before and after going solar. Be sure to check out the “Interesting Issue” near the end of this post.

Looking at a sample of page 2 of a PECO electric bill before going solar, you’ll see 

  • one meter reading showing monthly usage (451 kWh in our sample)
  • one fixed Customer charge of $8.44
  • three charges based on usage for Generation, Transmission & Distribution.

If you’ve gone to PAPowerSwitch and selected another electricity supplier, then you would see Generation & Transmission combined onto one line, with the rate set by that supplier.  

On your first month with solar, it will be a bit complicated for two reasons.

  1. PECO charges the installer for the new meter (part of your payment to the installer), and then PECO gives you a credit on your bill. The amount is between $300 and $400.
  2. You’ll therefore be billed part of the month with the old meter, and the remainder with the new meters.

You’ll see a bill like the one below with 3 meter readings:

  1. Old meter reading, partial month’s usage before switch to solar (sample: 81 kWh)
  2. New “in” meter (also called general service) for electricity you used from PECO (sample :232 kWh)
  3. New “out” meter, for electricity your rooftop system sent to PECO (sample 340 kWh)

plus a Customer charge of $8.43 (or 8.44, not sure why it varies a little).

What this means:
The energy from solar that was sent back to PECO was 27 kWh more than the amount received from PECO (340 – 232 – 81). This surplus 27 kWh will be banked towards next month’s use. You are billed just the Customer charge of $8.43 for the month.

 

To make it more complicated, for this particular bill, the 27 kWh surplus resulted in a  “Renewable Energy Credit” of $2.15 because the bill happened to be in May which is the month when PECO zero’s out the banked distribution of kWhs. They call this “settlement.”

This plus the credit mentioned earlier, for the meter, results in a total credit of $327.06.  Given that the customer charge was $8.43 the bill ends up with a credit of $318.63 that will be carried over to the next month. The image below is Page 1 of the May bill.
Note the “Message Center” which describes the “banked distribution” and the “settlement.”

The following months, when your grid-connected system is in full swing, you’ll see a bill like the one below:

  • 2 meter readings:
    “In” meter, for electricity you used from PECO,  (sample 287 kWh)
    “Out” meter, for electricity your rooftop system sent to PECO, (sample 525 kWh)
  • Customer charge $8.43

In the example, 238 kWh more electricity was sent to the grid than you pulled down  (525-287) . The surplus will go into your “banked distribution” and will be added to next month’s “out” meter reading to determine next month’s bill. If the total of these two is more than the “in” meter, then no charge, if it is ever less than the “in” meter, then you will see the three charges for generation, transmission and distribution for the extra kWh’s used.  This rollover and comparison will occur each month until the next May. In May, PECO will zero out the surplus “banked distribution” with a check or a credit on the bill.


INTERESTING ISSUE – There is one piece of usage information that is not visible on the PECO bill: How much electricity was actually consumed by the loads in the house. Since solar energy is used by the house loads first, PECO does not see this energy so can not meter this energy.

On the 13-Month Usage chart shown above, compare the usage for the prior year’s month of June, before the solar installation, to June of the current year which was after the solar installation. The current year is significantly lower than the prior year. This is because the big usage in June is the air conditioner, and the air conditioner tends to be on during the day when the sun is out and power is being generated by the panels. This is a clear picture of the value of solar because the electricity for the air conditioning load never had to enter the electrical grid. The electricity was consumed right where it was generated.   

The load information is not lost to the homeowner as it is being tracked by the monitoring system from the solar company which is used to track the output of the solar arrays.

This data in combination with the information available on the PECO bill will allow a full picture of the energy flow.

May 20th update on our 1st group of solar installs

Two more homes have their panels connected to the grid and generating electricity for a total of three!

See the updated chart below listing the steps required to fully implement rooftop solar, along with the status for each of our 12 initial households.

Green = number of households that have completed each step
Red = number of households not yet completed.

Dara Bortman from Exact Solar is managing each of these steps to ensure a smooth process.

Where are we with our 1st group of solar installs?

Kicked off last October, by the end of February, we had 12 area households step up for rooftop solar installations. Two and a half months later, 3 homes have panels on their roofs. One of these is connected to the grid and generating electricity.

We’ve learned there are quite a few steps to the installation process. See the chart below listing the steps required to fully implement rooftop solar, along with the status for each of our 12 initial households.

Green = number of households that have completed each step
Red = number of households not yet completed.

Dara Bortman from Exact Solar is managing each of these steps to ensure a smooth process.

Solar at the edge of the woods

Hearing about the 2015 Solarize Northwest Philly pilot program, and like me, having dreamt for over 30 years of solar panels powering her home, this resident of Marion Lane in Mt Airy went to a discussion at Germantown Friends Meeting last January.

She was impressed with Mark Bortman of Exact Solar and easy explanation of the process of joining the clean energy revolution. The discussions after Mark’s presentation really helped to cinch her decision to invest in rooftop solar, and, as the story goes, she signed up on the last day of the program.

photo: Exact Solar

The system of 19 panels cost her $15,000, with the final cost about $10,000 after the federal tax credit. It is designed with a 4.94 kW capacity generating about 5100 kWh per year, which is pretty good for a flat roof with some shade. There are even 2 panels on the tiny front roof, at the far end of this photo.

Why did she spend such a large chunk of her retirement funds into something on her roof that she never really saw? She tells me in one word: Climate.

The system should pay for itself over time with the greatly reduced PECO bills. The solar installation covers 100% of her electric usage except in the winter.

 

Solar in our Midst

Pole Mounted Solar for the backyard

A friend in Flourtown really wanted to go solar, except that she had a tiny roof and two beautiful gigantic spruce trees near her house which made it difficult.  However, she also lived at the end of a street and her backyard faced a field with trees in the distance. She decided to put up a 12 panel solar array mounted on a pole.  With the assistance of a solar installer, she worked through all the details including trenching the cable back to the house, and she now has a very large, and to some, beautiful, structure in her backyard. It is invisible to the street.

The system is rated for 3.5 kW (kilowatt), which means at peak sunlight she would get more power than she currently needs, even with the planned electric car and the high efficiency heat pump she hopes is in her future. Over  the course of the year she should see a net contribution to the utility grid with a check from PECO, our local power company,  to pay her for that extra power that has gone from her house to power other people’s houses.

On October 5th, 2016 she turned on her own personal electrical power plant. This is similar to solar on a rooftop, but feels more substantial when it sits in the back yard. The panels, US made by CertainTeed, are wired in series and lead into a giant inverter on the back of the pole with a meter showing power generation.  

On December 13th at 9:30 AM, when this picture was taken, it was generating 492 watts as the sun rose over the trees, increasing to 860 watts by 10 AM on a grey day.   Note that this was very near the winter solstice — in other words, hardly optimal “sun” time. 

There is an “eye” on the top of the panels that is watching the sun and it will tell the mechanism behind the panels to adjust the panels so they are at an optimal angle to the sun. This system does bidirectional tracking (east/west plus more/less tilted to the sky). This cost for this about $2200 more, but should increase output by 33%, estimated to generate about 4690 kWh the first year. 

In June, expect to see sunflowers planted along the walkway, that have known how to track the sun for eons. The solar panels reset to the southeast every night, ready for the sun to come up the next day.

This is a small system capacity by any standard, but felt enormous as we stood beside it, towering beside the decades tall spruce trees. In an effort to merge this large object with the landscape, the owner added landscaping around the panels to soften their visual impact, using only native plants, most of which will provide food to butterflies and bees, come warmer weather. Shocked by the size of the panels, the owner reached out to her neighbors to reassure them that the new plantings would mostly cover the backside of the panels, but most didn’t seem to be bothered by the visual, and instead complimented her.

The inverter, by Fronius, converts the direct current (DC) that is produced by the solar panels to alternating current (AC) that is needed for all the electrical loads inside the house.  The AC current is sent down a wire inside a conduit which goes underground then through the basement to a meter in the front of the house. 

This meter is paired with another meter that comes in from the power company. One meter calculates the energy being sent out to the power company and the other tracks the power coming into the house from the power company. There is also a very important shut off box that is needed to cut the power from the solar panels in case of a fire or other emergency.  She is working with the local fire house to figure out the best way to notify fire fighters about this box. It may be a sticker next to her “Save my pets” sign on her front door, already addressed to them.

We saw a cool tracking app made by Fronius, the company that made the inverter. This homeowner is now not only a tree-hugger but also an inverter hugger, saying she loves her Fronius! I can see why; the phone-based application shows the energy generated in the past few days, as well as the cumulative the CO2 reduction, the money saved, and equivalent trees planted. The EPA’s greenhouse gas equivalencies calculator shows that generating 4690 kWh with solar panels is like reducing 3.3 metric tons of CO2 from the atmosphere, or not driving 7899 miles driven by an average passenger vehicle, or switching 117 incandescent lamps to LEDs, or the carbon sequestered by 85 tree seedlings grown for 10 years. 

The cost of the system was just under $20,000.  She will get 30% of this back when she files her taxes because of the federal tax credit that is in place until 2019. She will also receive a small amount of money for the solar renewable energy certificates (SRECs) from the power company, a monthly savings on her electric bill since she won’t have to buy the electricity from PECO, plus an annual check for all the surplus energy that she generates.

She figures 8 to 9 years for this system to payback, but the real payback has already happened.  She loves her panels, loves her inverter and is very happy knowing she’s making her own clean power.

How and Why We Went Solar

While sharing stories of families in northwest Philadelphia that’ve invested in rooftop solar,  I came across this one by Virginia Thompson in Swarthmore about her own family’s journey. I suspect this is part of Transition Town Media‘s effort to Solarize Greater Media.

image courtesy swarthmorean.com

http://www.swarthmorean.com/articles/how-and-why-we-went-solar/