PanelCensus

621 Energy

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Solar installer based in Massachusetts · active in 2 states · installer record #100 resolved from 75 public installation records.

At a glance

621 Energy is a solar installer with 75 recorded installations totalling 4.6 MW, dated 2012 to 2025. Its records are concentrated in Massachusetts (109%), where it ranks 101st of 463 profiled installers by volume and 2,770th of 10,536 nationally. The median installed price across 79 priced systems is $3.35/W before incentives.

Recorded installs
75
Total capacity
4.6 MW
DC nameplate
Median system
30.1 kW
≈ $95,813
Median price
$3.35/W
pre-incentive · 79 priced
Third-party owned
15%
lease / PPA
Battery attach
0%
First recorded
2012
Last recorded
2025

Track record

Install volume by year

2012
1$3.72/W
2013
3$3.40/W
2014
6$4.56/W
2015
4$3.60/W
2016
9$3.91/W
2017
10$3.57/W
2018
7$3.26/W
2019
11$2.90/W
2020
7$3.09/W
2021
5$3.85/W
2022
5$2.23/W
2023
4$2.22/W
2024
9$3.55/W
2025
2$2.07/W

Bars: recorded installs · right column: this installer's median $/W that year.

Latest records

Most recent recorded installs

DateLocationSizePriceOwnership
Feb 27, 2025Marlborough, MA175.7 kW$377,712Third-party
Jan 22, 2025Manchester, NH76.4 kW$151,351Host-owned
Nov 20, 2024Manchester-By-The-Sea, MA291.8 kW$754,853Third-party
Mar 22, 2024Natick, MA13.6 kW$49,226Host-owned
Mar 5, 2024Acton, MA38.4 kW$240,389—
Mar 5, 2024Acton, MA38.4 kW$240,389Host-owned
Mar 5, 2024Acton, MA38.4 kW$240,389Host-owned
Jan 29, 2024Cambridge, MA30.1 kW$99,000—
Jan 29, 2024Cambridge, MA30.1 kW$106,600—
Jan 29, 2024Cambridge, MA30.1 kW$99,000Host-owned

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Service geography

Massachusetts
82
New Hampshire
1

Busiest cities

Cambridge, MA 10Acton, MA 8Boston, MA 5Needham, MA 4Melrose, MA 3Becket, MA 3Sharon, MA 3Arlington, MA 2

Record

Installer ID
PC-100
First recorded install
Dec 26, 2012
Last recorded install
Feb 27, 2025
Priced records
79

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How does 621 Energy compare with other installers in Massachusetts?

By recorded installations 621 Energy ranks 101st among the 463 installers based in Massachusetts with five or more records. Its median price of $3.35/W is about 20% below the Massachusetts median of $4.17/W (the installer's median covers every state it works in). Its median system, 30.1 kW, is about 4.0 times the state median of 7.5 kW. 15% of its recorded installations are third-party owned (lease or power-purchase agreement), against 47% across Massachusetts. 0% include battery storage, compared with 4% of Massachusetts records. Installers of similar recorded volume in Massachusetts include Steele Hudson (78), Zapotec Energy (77) and Katelin Brown (76).

How has 621 Energy's installation volume changed?

621 Energy's earliest dated installation on record is from 2012. It has recorded installations in 14 calendar years. The busiest year was 2019, with 11 installations. 2025, its latest year with records, has 2. Its median price per watt moved from $3.72/W in 2012 to $2.07/W in 2025. The most recent recorded installation is dated Feb 27, 2025.

Where does 621 Energy install solar?

Recorded installations span 2 states: Massachusetts (82, 109%) and New Hampshire (1, 1%). The cities with the most of its installations are Cambridge, MA (10), Acton, MA (8), Boston, MA (5), Needham, MA (4) and Melrose, MA (3).

Frequently asked questions

How many solar installations has 621 Energy completed?

PanelCensus records 75 installations by 621 Energy, from Dec 26, 2012 to Feb 27, 2025, totalling 4.6 MW of capacity. Public reporting varies by state, so the company's true total may be higher.

What does 621 Energy charge for solar?

The median installed price across 79 priced systems is $3.35/W before incentives (median system 30.1 kW, about $95,813). The Massachusetts median is $4.17/W.

Where does 621 Energy install solar?

Recorded installs span 2 states, led by Massachusetts (82) and New Hampshire (1). Its busiest city is Cambridge, MA.

Is 621 Energy still installing solar?

The most recent installation attributed to 621 Energy in the public records is dated Feb 27, 2025; 2025 has 2 recorded installations. Records reach PanelCensus months to a couple of years after installation, so recent activity may not appear yet.

Does 621 Energy install leased or PPA solar systems?

11 recorded installations by 621 Energy (15%) are third-party owned — a lease or power-purchase agreement; across Massachusetts the share is 47%.

Does 621 Energy install battery storage?

0 recorded installations by 621 Energy (0%) include a battery.

Related installers and places

Dataset updated . Sources: LBNL Tracking the Sun + permit and program records; installer resolved by exact-normalized name matching.

About this data

Source: Lawrence Berkeley National Laboratory's Tracking the Sun, merged with city permit records, state incentive programs and the USGS U.S. Large-Scale Solar Photovoltaic Database / EIA-860 plant registers, as published September 21, 2026 — PanelCensus refreshes it as each source publishes new records. See the methodology for how records are matched, cleaned and scored.

Cite as: PanelCensus, “621 Energy, solar installer (Massachusetts)”, https://panelcensus.com/installers/massachusetts/621-energy-100 (data as of September 21, 2026).