Solarize bulk-buy campaigns
Neighbours sign up together in a short, time-limited campaign to buy rooftop solar from one vetted installer at a group price, so each household owns its own panels for less.
Start small
Form a team of 3 to 5 volunteers with a council or community group as trusted host. Spend 1 to 2 months writing a simple installer RFP (references, capacity, warranty, tiered pricing) and picking one installer, then run a 8 to 12 week sign-up window with 2 to 4 public workshops. US DOE guidance puts website and materials at about USD 3,000 to 10,000 and marketing at about USD 10,000 to 50,000; a single neighbourhood pilot can run on far less, as Solarize Portland's first campaign did with mostly flyers and volunteer time.
The problem
Lack of access to affordable renewable energy, and fossil fuel dependence and its economic impact. Households face high upfront prices, confusing quotes and installer distrust, so rooftop solar stays slow to spread even where it pays back.
Where it fits
Thrives where homeowners have suitable roofs, there is a working net metering or export tariff and some incentive, and a trusted local body (neighbourhood coalition, council, energy agency) can run outreach. Needs a competitive installer selection (RFP), a tiered price that falls as more people sign, a hard deadline of roughly 6 to 20 weeks, volunteer 'solar ambassadors', and free public workshops. Started in Portland, Oregon in 2009 and spread through US states, UK councils (Solar Together), Dutch and Belgian municipalities (iChoosr) and Victorian councils in Australia.
The principle underneath
Aggregating many small buyers into one time-boxed, competitively tendered order cuts the installer's customer acquisition cost and the buyer's search and trust costs at once, while visible neighbours going first creates social proof and a deadline turns intention into action.
Who to call
Energy Trust of Oregon (publisher of The Solarize Guidebook); Southeast Uplift Neighborhood Coalition, Portland; Solar Oregon; Connecticut Green Bank (SmartPower ran Solarize CT); Massachusetts Clean Energy Center (Solarize Mass); Greater London Authority Solar Together team; iChoosr (runs Solar Together and Dutch/Belgian group buys); Central Victorian Greenhouse Alliance and City of Darebin (Solar Savers); US DOE Solar Energy Technologies Office; Solar United Neighbors.
Watch out for
Choosing the installer without competition or proper checks on capacity and references; installer overwhelmed by volume and installs slip months; no follow-up checks on contract and install quality; campaign ends and momentum collapses; benefit flows only to affluent owner occupiers; local installers feel shut out and the scheme loses goodwill; battery and storage add-ons need much more legal and technical review than panels alone.
Where it comes from
Grassroots origin in 2009 when Mount Tabor resident Stephanie Stewart approached Southeast Uplift Neighborhood Coalition in Portland, Oregon, with Energy Trust of Oregon designing the program and contractor RFP. Codified in The Solarize Guidebook (NREL/US DOE with Portland partners) and replicated by state agencies (Connecticut, Massachusetts), councils (Greater London Authority, Victorian alliances) and the iChoosr group-buy model in Europe. Open public knowledge; no custodial protocols.
Where it's worked
Netherlands (iChoosr municipal group buys) · 2008 to present
Operator reports 1,000,000 solar panels installed in the Netherlands through collective purchasing (company claim, not independently verified).
Stories from the fieldSource
Southeast Portland, Oregon, USA (Solarize Portland) · 2009 to 2010
About 350 homes enrolled in a six-week window; 120 installations totalling 347 kW by February 2010, at USD 6.80/W, about 24% below the Q2 2009 Portland average of USD 8.95/W.
DocumentedSource
Oregon, USA (statewide Solarize campaigns) · 2009 to about 2013
More than 20 campaigns, 3,100 homeowners enrolled and about 1,000 systems installed; in 2010 Solarize was about half of Energy Trust's residential solar activity.
DocumentedSource
Connecticut, USA (Solarize Connecticut, 34 municipalities) · 2012 to 2015
Roughly doubled installations in treated towns (about 27 extra per town) and cut pre-incentive prices by about USD 0.64/W; programme cost about USD 900 per induced installation. Published in Management Science (2021).
Peer reviewedSource
Massachusetts, USA (Solarize Mass, 17 communities) · 2012 round
802 residents and businesses signed contracts for 5.1 MW; installers hired 32 staff.
DocumentedSource
London, UK (Solar Together London, Greater London Authority with iChoosr) · 2017 to 2021
Solar installed on over 1,000 homes across phases 1 to 3; most recent phase averaged a 33% saving against typical market price, and phase 4 drew over 2,700 sign-ups.
DocumentedSource
City of Darebin, Victoria, Australia (Solar Saver) · 2013 to 2014 onward
More than 300 low-income pensioner households got 1.5 to 2 kW systems with no upfront cost, bulk-bought by council at about AUD 2,909 each and repaid through a special charge on rates over ten years.
DocumentedSource
Where it failed
Gains were smaller or absent when the installer was not chosen competitively: the Connecticut Solar Challenge variant without competitive bidding produced fewer extra installations and no price reduction in its first six months (Gillingham and Bollinger). Towns picked at random rather than self-selected got roughly half the uplift, so it needs local champions. The Connecticut study found no lasting boost after the campaign ended. In Portland a small established installer said in 2011 that concentrating each campaign on one contractor squeezed independent firms and pushed prices below what he could afford. Standard campaigns mostly reach better-off owner occupiers; renters and low-income households are left out unless special finance (council rates charges, no-credit leases) is added.
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