Charts showing cumulative production

The NW Philly Solar Co-op organized 2 buying groups. All are installed and fully operational. Marion likes to periodically check on each project and chart the data for the 27 households.

Chart 1 shows the step up in installed capacity from April 2017 thru May 2019 — when we managed these projects.

Chart 2 shows the combined electricity generated over the years.

Chart 3 stacks up the generation over the years.  Kinda cool!

On average, these households generate about 440 kWhs per day, and will continue to do so over the next 20 years. Our personal investments generate clean energy not only for our homes, but also add clean energy to the grid when we’re at work.

Time to lobby for Community Solar

We’ve learned that PA Senator Mario Scavello (R-Monroe) has crafted a memo about bringing Community Solar to Pennsylvania.

Days later, PA Representatives Aaron Kaufer (R-Luzerne), Donna Bullock (D-Philadelphia), Peter Schweyer (D-Lehigh) and David Millard (R-Columbia) have proposed a similar memo for the house.

So what is community solar?

With community solar, you can subscribe to a portion of an offsite [not on your own roof] solar project and receive credit on your electricity bill for the power produced, just as if the panels were on your roof. Think of it like community supported agriculture (CSA) for your electricity needs! The farmers get a committed customer base, and can plan their investments for the coming years.

Many of us can’t invest in solar on our own roofs, for a number of reasons. It could be that we’re renters, live in an high-rise condo, or have a shaded or otherwise inappropriate roof for solar. Or, it could be that we’re  not sure how long we may stay in our current home.

image credit: Sierra Club |

Community solar gives citizens and businesses the choice to participate—there is no mandate for participation or request for state funding. By passing this legislation, Pennsylvania would join 18 other states in giving its residents and businesses the opportunity to acquire solar energy from a community solar project.

Community Solar simply removes an existing policy and market barrier, allowing for much greater participation in electricity by solar for individuals, business and farmers.

How can you support Community Solar?

Write, call or tweet  your PA State Senator & Rep, asking them to support Senator Scavello & Representative Bullock’s initiatives to bring Community Solar to PA.

Don’t know your legislators in Harrisburg? Find them here.

National Solar Home Tour – Oct 6 & 7

Curious about rooftop solar? Many people in our region are happy with their investment & installation, and are showing off their systems and stories at the upcoming National Solar Tour. 

The American Solar Energy Society ( has been doing this tour every year for at least 30 years. It’s a chance for people considering rooftop solar to meet their neighbors, check out their systems and actually see what it’s like to be part of the clean energy revolution. 

Free and open to the public – all welcome!  Find a house near you and take the tour! 

  • Sat Oct 6 @ 10 – 5 / 616 Oak Park Rd, Hatfield PA / register here / We have a brick rancher built in 1960. In addition to the solar electric we have 2 4×10 solar hot water panels heating a storage tank holding about 400 gallons of water. It’s a non pressurized drain-back system. We insulated the house with soy foam and cellulose. We have rain barrels, a rain garden, honeybees, our yard is filled with plants that support bees and pollinators. 
  • Sat Oct 6 @ 10 – 2:30 / 566 Jamestown St, Philadelphia PA / register here / Ballasted system connected to first floor apartment in a two story row home. Excess credited to owner’s residence about 10 houses away in the same block. In Pennsylvania this is called virtual meter aggregation. The house with the PV system is at a very busy, very visible corner.
  • Sat Oct 6 @ 10 – 6 / 100 College Ave, Flourtown PA / register here / Because I have a shady roof, I opted for a pole-mounted system in my backyard. It does bidirectional tracking. 
  • Sat Oct 6 @ 5 – 7 / 8634 Millman Pl, Philadelphia PA / register here / After we lost three trees on the south/west side of the house last year, just enough sunlight became available to make solarizing worthwhile.
  • Sun Oct 7 @ 1:30 – 5 / 401 Crescent Rd, Wyncote PA / register here /  The 7.92 kW PV system, installed in 2012, is part of a comprehensive renovation of a 1950s home for maximal energy efficiency, comfort, and aesthetic appeal.  Additional conservation measures include insulation, geothermal heating and cooling, passive solar features (e.g. maximizing use of natural light), and energy-efficient appliances and lighting. 
  • Sun Oct 7 @ 2 – 5  / 325 S 25th St, Philadelphia PA / register here / Our original solar system was installed in 2010 (4.3 kW). We expanded our system in 2017, adding 4.8 kW. In 2018 we added integrated EV charging inverter to charge Chevy Bolt EV.

Have questions that remain unanswered? We’re local, and here to assist! Write us at

Ask your state Senator to support SB1039

Live in a condo, townhouse, or just a house with a home-owners association? And getting resistance when you’ve tried to install rooftop solar?

Senate Bill 1039, sponsored by Senator Andy Dinniman, could remove obstacles to residential rights to solar energy, and make it easier for more of us to invest in rooftop solar.

This bill has 3 other co-sponsors by now: Senator John YudichakJohn C. Rafferty, Jr.Senator Tina Tartaglione, and has been referred to the Urban Affairs & Housing Committee on 2/9/18. 

We need to make it easier for people to invest in renewable energy. A resident of Newtown who would like to install rooftop panels faces opposition from her home-owners association. Her Senator Chuck McIlhinney supports SB 1039 as well.

Please ask your state Senator to co-sponsor SB 1039.

Not sure who’s your state Senator? Type in your address here and find out! Then make sure to ask them to co-sponsor SB 1039.

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], and have a sun-charged day!

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.

We have a 2nd group buying rooftop solar

Congratulations to the 14 households joining the clean energy revolution by electing the Northwest Philly Solar Co-op and Solar States for their rooftop solar installations. Soon, they’ll be making their own electricity!

Together, these systems total over 64 kW and should generate 75,935 kilowatt-hours (kWh) each year. Based on the EPA’s greenhouse gas equivalencies calculator, this should offset 124,588 pounds of carbon dioxide each year. That’s 56.5 metric tons! This is also equivalent to taking 12.1 passenger cars off the road, or the amount of CO2 sequestered by 66.6 acres of US forests. Hard to believe, right?

How soon might each household be making their own electricity? Though an installation may take only 2-3 days, the whole process from signing a contract to PECO “flicking” the switch could take 4 to 5 months. Because, in between, the installer (Solar States) applies and waits for approval from the utility (PECO) and the municipality (City of Philadelphia) before scheduling their own team for the install.  Once installed, both utility & municipality inspect the installer’s work and grant them permission to operate. So, expect an early summer switchover.

Our team at the Northwest Philly Solar Co-op will be tracking each install with weekly calls to the installer and updating the progress chart shown below.

Y – axis lists stages of installation. X – axis is count of households. Green = completed stage, Red = incomplete stage. This is a group process, not a competition. And we’ll be pushing to get each of your installations completed.

We want to hear from you, especially if you have any questions or surprises along the way. Please write or call Marion Biddle (215.740.1080) or Meenal Raval (267.709.3415). And thank you for joining the rooftop revolution!

call to action: close the borders to all out-of-state solar

We have spoken to many of you about the necessity of closing the borders of PA to improve the market for SRECs.  Last fall, a bill was recently approved to do just that, but if the PUC does not interpret the bill as it was intended, pricing will never go anywhere. Please read the below and sign on to one of the linked petitions or write your own letter.  It is imperative that we speak in volume and in one voice.

Image credit:

Tell the PUC to get the solar border law right.

In an unusual show of bipartisan support for clean energy, the Pennsylvania General Assembly passed Act 40 in October 2017. The intent of the law was to “close” the solar renewable energy credit (SREC) “border” by permitting only in-state solar systems to qualify for Pennsylvania’s SRECs. Previously, the state’s “open borders” practice allowed systems in 12 other states (and D.C.) to receive our credit. This resulted in an oversupply of SRECs, a loss of investment in Pennsylvania’s solar market, and to other states getting solar jobs that should have been created here.

The Pennsylvania Utility Commission (PUC) must now implement Act 40. Unfortunately, in December the PUC took a stunningly bad first step with a tentative implementation order that relies on a flawed legal interpretation of Act 40.  Under the PUC’s interpretation, all existing out-of-state solar systems would be grandfathered and could continue to receive Pennsylvania’s SRECs. This legal interpretation is completely counter to the intent of the law and would make Act 40 utterly useless.

PUC Chairman Brown and Vice Chairman Place issued their own interpretation of Act 40 that does accurately interpret the law as it was intended. [Read the Post-Gazette article that nicely details the differences.]

As a Pennsylvania solar owner you know how the value of the SREC has dropped dramatically. Virtually, the only chance in raising the value of the SREC in the near term is to enact the bill correctly to no longer permit out of state systems. Of course, there is no absolute guarantee that the price will go up with or without the bill. We now have until February 6 to submit public comments to the Commission. Here’s how you can do that:

Add your name below

1) Add your name to this sign-on letter to join solar owners across the state to tell the PUC to accurately interpret and implement the law as the General Assembly intended. [PREFERRED METHOD] OR

2) Submit individual comments to the PUC electronically (first, set up an individual or corporate account, then log-in and upload your comment file here, docket # M-2017-2631527) OR by sending a letter addressed to: Secretary, Pennsylvania Public Utility Commission, Post Office Box 3265, Harrisburg, PA 17105-3265 referencing docket number M-2017-2631527.

Thank you! 

Our 2nd buying group – now closed

Live in the Northwest? Have a sunny roof? Wondering how to harvest that roof to generate your own electricity?

We invite you to consider joining our second buying group. It’s in full swing now, with Solar States as our selected installer. We have secured excellent group pricing, with price breaks at 5, 10 and 15 households.

Having educated over 40 households about their options with rooftop solar in just the last couple of months, we’re confident we can answer yours as well!

Call Meenal at 267.709.3415 or write or look for us at these upcoming events in the neighborhood…

  • Friday November 3rd @ 5pm at the Weavers Way Fall General Membership meeting
  • Monday November 6th @ 7pm at our informational gatherings next door to Weavers Way Mt Airy, 555 Carpenter Lane, Philadelphia
  • Monday November 20th @ 7pm, also at 555 Carpenter Lane, Philadelphia

Know that you have until December 15th to join this buying group. So help yourself, and help a neighbor, by buying rooftop solar as a group! Get started now…

[contact-form-7 id=”662″ title=”sign-up-form”]

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!