Utility Hosting Capacity Maps
Feeder-level hosting capacity from every utility we cover — on the same map as parcel ownership, substations, and live interconnection queue data.
Explore the Map
Good data, trapped in the wrong tool
Utility hosting capacity maps are the single most useful public dataset in distributed solar development. They tell you, circuit by circuit, roughly how much generation the distribution system can absorb before upgrades get expensive — which is the question that decides whether a site is worth pursuing.
They are also published one utility at a time, in standalone GIS viewers that contain nothing else. No parcel boundaries. No ownership. No interconnection queue. No wetlands, slope, or protected areas. Screening a region means a portal per utility, then cross-referencing county parcel viewers and DPS queue spreadsheets by hand. Nobody stops doing it — it's the job. What happens is that it becomes somebody's job: most developers are paying one or two analysts to maintain a screening spreadsheet that goes stale the month it's finished, and the real cost isn't their time, it's the sites nobody got to.
Sungarden syncs each utility's published data and puts it on one map with everything the portals leave out. Read more about how the underlying data works in our guide to utility hosting capacity maps.
New York hosting capacity maps
New York runs distributed generation interconnection through Standardized Interconnection Requirements, with required system upgrades identified and estimated in the utility's CESIR study. We cover 5 utilities in New York.
- National GridUpstate New York — roughly 24,000 square miles from the Capital Region west to Buffalo and north to the Canadian borderFeeder hosting capacity · Parcel ownership · Interconnection queue
- NYSEGRoughly 20,000 square miles — about 40% of upstate New York — in non-contiguous pocketsFeeder hosting capacity · Parcel ownership · Interconnection queue
- RG&EA nine-county region centered on RochesterFeeder hosting capacity · Parcel ownership · Interconnection queue
- Central HudsonThe Mid-Hudson Valley across Dutchess, Orange, Ulster, Sullivan, Greene, Columbia, Putnam and Albany counties, plus parts of Delaware and SchoharieFeeder hosting capacity · Parcel ownership · Interconnection queue
- Orange & RocklandOrange and Rockland counties plus parts of Sullivan and Delaware countiesFeeder hosting capacity · Parcel ownership · Interconnection queue
Coverage we're working on
Maine is next — Central Maine Power and Versant feeder and substation data are already loaded, with landing pages to follow.Interconnection queue coverage is already national: NYISO, PJM, MISO, CAISO, ERCOT, ISO-NE, and SPP queues are all re-synced every fifteen minutes and mapped, even in territories where we don't yet carry hosting capacity.
Developing somewhere we don't cover yet? Tell us where — coverage requests genuinely drive what we build next.
Frequently asked questions
What is a hosting capacity map?
A hosting capacity map shows how much distributed generation a distribution circuit can accommodate without violating the utility's technical criteria. Utilities publish it per line section or feeder, usually as a minimum and maximum, so developers can screen locations before filing an interconnection application. These values are calculated for a specific assumed generation type and loading condition — typically inverter-based PV at a stated power factor — so they do not transfer cleanly to storage, hybrid, or rotating-machine projects.
Why do utilities publish hosting capacity at all?
Mostly because regulators required it. New York's Reforming the Energy Vision proceedings and comparable dockets in other states pushed utilities to publish distribution system data so that developers could self-screen instead of filing speculative applications that clog the queue and burn utility study resources.
What do minimum and maximum hosting capacity mean?
Utilities publish a range reflecting the highest and lowest results across the points they analyzed on a circuit. On long rural radial feeders capacity often does thin with distance from the substation, but the profile is not a smooth taper and not always in that direction: voltage regulators and capacitors create step changes, conductor size and load distribution create local highs and lows, and several of the strictest criteria — ground fault overvoltage and effective grounding, substation transformer and bus limits, reverse power flow through the LTC — bind hardest at the substation. Utilities test a stacked set of criteria: steady-state overvoltage and voltage regulation, thermal ratings, ground fault overvoltage, protection coordination and fault current, unintentional islanding and minimum-load ratios, and reverse power flow. Some are distance-dependent; several are not. Treat the published range as a screening band for the circuit, not a value you can interpolate for a specific parcel.
Does hosting capacity tell me what interconnection will cost?
No, and the gap is bigger than it looks. Costs come out of the utility's impact study — a CESIR in New York — and the largest line items there are usually station-level and protection scope: station breakers and bays, transformer bank work, sub-transmission work, direct transfer trip, relay and telemetry upgrades. Almost none of that is visible on a feeder hosting capacity map. Feeder headroom plus a clean queue is a necessary condition for a cheap interconnection, not a sufficient one. What screening buys you is not paying a study deposit on sites that were never going to work.
Why isn't the utility's own portal enough?
Because a capacity value on its own isn't actionable. The portals are standalone GIS viewers with no parcel boundaries, no ownership information, and no link to the interconnection queue. You can see that a feeder has headroom, but not who owns the land under it, whether the ground is buildable, or how many projects are already queued at the substation it feeds.
Screen a county in an afternoon.
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