Saying "100% renewable" without explaining what is actually flowing through your wires.
Almost every Green Mountain Energy review repeats the headline: 100% renewable, since 1997, the first REP in the country to sell wind and solar to households. All of that is true. What the reviews skip is the part that confuses customers when they read their first bill.
The electrons in your home outlets are the same ones your neighbor gets. ERCOT runs one Texas grid. Every kilowatt-hour that lands at your meter is a blend of whatever was generating at that moment: roughly 30% wind, 10% solar, 40% natural gas, with the rest from nuclear and coal. There is no separate "green wire" running into a Green Mountain customer's house.
What you actually buy is a REC: a tradable certificate that says one megawatt-hour of renewable energy was generated somewhere on the grid and that the environmental attribute now belongs to you. Green Mountain retires one REC for every MWh you use. The dollars fund renewable generators. The label on your account is real. The electrons in your kitchen are still the same ERCOT mix.
How a Green Mountain plan is actually built.
Same three-layer stack as every Texas REP, with one extra step bolted into layer 1: the REC purchase.
Layer 1, Green Mountain
Energy charge + REC
Per-kWh wholesale power, hedged by NRG's trading desk, plus the cost of retiring 1 REC per MWh on your behalf. The REC line is the green premium baked into the rate.
Layer 2, Green Mountain
Base monthly fee
A flat dollar amount Green Mountain adds every month, often $0 on Pollution Free residential plans and disclosed on the EFL. Affects the effective rate most at low usage.
Layer 3, Your TDU
TDU pass-through
Oncor, CenterPoint, AEP or TNMP delivery charges, set by the PUCT and passed through with zero markup. Identical whether you pick a green or gray REP.
The green premium lives entirely in layer 1. Layer 2 is small. Layer 3 does not move. Anyone quoting a "renewable surcharge" on layer 3 is misreading their bill.
Green Mountain's Texas plans, decoded.
The brand markets five recurring plan archetypes in Texas. Each is 100% renewable via RECs; the shape and fit differ.
| Plan family | Type | Term | Best for | Watch out for |
|---|---|---|---|---|
| Pollution Free e-Plus (fixed) | Fixed price per kWh | 12, 24 or 36 mo | Most households wanting price stability | ETF if you leave early; auto-roll to variable at end of term |
| Solar Buyback | Fixed + export credit | 12 or 24 mo | Homes with rooftop solar exporting to the grid | Buyback rate often capped at the energy rate, not retail |
| Free Power Saturdays / Nights | TOU variant of fixed | 12 or 24 mo | EV owners, weekend laundry shifters, night-cycling pools | Loaded weekday/peak rate offsets the "free" hours |
| Pollution Free EV | Fixed with overnight EV credit | 12 or 24 mo | EV households charging at home overnight | Credit only triggers above a minimum kWh shifted to off-peak |
| Pollution Free Business | Custom commercial | 12 to 60 mo | SMB, retail, hospitality wanting a green claim | Quotes are broker-routed; always benchmark two other brokers |
Plan names and rates are updated quarterly by Green Mountain Energy; always pull the live EFL from the brand's site or Power to Choose before signing.
The green premium is roughly 1 to 3 cents per kWh.
At the average Texas household usage of 1,176 kWh per month, a 1 to 3 cent green premium adds about $14 to $35 to your monthly bill compared to a non-renewable fixed plan from a non-NRG REP.
Why a range and not a single number: REC prices fluctuate, and each Texas REP packages them differently. Green Mountain's premium tends to land at the upper end because the brand sells the green attribute as the core product. Plans badged "100% green" from gray-default REPs (TXU, Reliant, Constellation) often sit lower because they hedge in bulk.
The honest framing: you are paying $14 to $35 a month to fund roughly 14 MWh of renewable generation per year. Whether that is the most efficient climate dollar you can spend depends on your alternatives (rooftop solar, efficiency upgrades, IRS heat-pump credits, community solar).
typical Green Mountain premium per month
How a Vermont startup became NRG's green-label brand.
A 30-year timeline from a Vermont utility offshoot to a Houston-based Fortune 500 subsidiary serving seven states.
1997, South Burlington, Vermont
Green Mountain Energy launches as an offshoot of utility Green Mountain Power, backed by entrepreneur Sam Wyly. It is the first US retailer to sell electricity as a branded 100% renewable consumer product.
September 2000, HQ moves to Austin
Anticipating the Texas retail-electricity opening, the company relocates its headquarters to Austin to be on the ground when ERCOT customer choice goes live.
January 2002, first green REP in Texas
Texas opens its retail electricity market under SB7. Green Mountain Energy is the first REP to certify a 100% renewable residential product in the state.
November 2010, NRG acquisition
NRG Energy acquires Green Mountain Energy for $350 million. The brand joins Reliant Energy, which NRG bought in 2009, under one parent. Direct Energy follows in January 2021 to complete the trio.
2026, the REC mechanism today
Green Mountain retires RECs for every customer kWh against ERCOT-area wind and solar generation. ERCOT itself is now ~30% wind, ~10% solar by annual energy share, so the REC pool tracks the grid getting greener even when no Green Mountain electron is physically routed to your house.
The honest summary: Green Mountain Energy is real renewable demand financed by real customer dollars. It is not a physical wire to a wind turbine. Both can be true at once, and the EFL discloses exactly which one you are buying.
5 mistakes Green Mountain shoppers make.
Five recurring patterns from real Green Mountain contracts. Each one is fixable before you sign.
If Green Mountain fits, also price-check the cousins.
All three NRG brands buy from the same wholesale desk. The branding diverges; the power source does not.
Layer 3 is set by your ZIP, not your green label.
Whichever Texas REP you pick, the wires company is fixed by your address. Find yours and you know the floor of your bill.
What to do before you sign with Green Mountain.
Pull last 12 months of kWh
From your current bill or your TDU portal. Average summer and winter separately. This is the number every EFL is graded against.
Read the EFL, not the badge
Confirm 100% renewable on the EFL itself, plus base fee, credit thresholds, ETF and post-term auto-roll rate.
Price the green premium
Compare Green Mountain to at least one gray-default 100% renewable plan and one plain fixed plan from a non-NRG REP. Decide if the premium is worth it for you.
Calendar your end date
The day you sign, set two reminders: 60 days before expiry and 7 days before. Auto-roll to variable is where most long-term cost hides.
If you struggle to pay
Texas runs LIHEAP as the CEAP program via TDHCA. Apply before disconnection; Green Mountain must offer a deferred payment plan.
Contact support
Existing customers: 1-866-785-4668. New TX orders: 1-833-561-6993. Outage and meter issues: your TDU, not Green Mountain.
Common questions about Green Mountain Energy in Texas.
No. Every Texas address draws from the ERCOT grid, which is a real-time blend of all generators running at that moment (roughly 30% wind, 10% solar, 40% natural gas, with the rest nuclear and coal). What Green Mountain Energy does is buy and retire one REC per MWh you use, so the environmental attribute of an equivalent amount of renewable generation is credited to your account. The label is real; the electrons in your outlets are the standard ERCOT mix.
A Renewable Energy Certificate is a tradable credit representing the environmental attributes of 1 megawatt-hour of renewable generation injected into the grid. When you buy a 100% renewable Green Mountain plan, the company retires one REC for every MWh of your consumption. RECs fund renewable generators by giving them a second revenue stream beyond the wholesale price of electricity. They are how every US 'green' retail plan documents its claim, regulated under each state's renewable portfolio standards.
Green Mountain Energy is a wholly-owned subsidiary of NRG Energy, Inc. (NYSE: NRG), headquartered in Houston. NRG acquired Green Mountain from its previous owners for $350 million, with the deal closing in November 2010. NRG also owns Reliant Energy (since 2009) and Direct Energy (since January 2021), so all three Texas brands share the same parent and the same wholesale trading desk.
Marketing positioning, not power source. Green Mountain leans on 100% renewable and the Pollution Free line. Reliant emphasises smart-home perks. Direct Energy markets solar add-ons and reward credits. All three buy from the same ERCOT wholesale market through NRG's desk, pay the same TDU pass-through and are regulated by the same PUCT. Spread at 1,000 kWh on equivalent fixed plans is usually $5 to $15 per month.
For existing residential customers: 1-866-785-4668. For new Texas orders: 1-833-561-6993. For a power outage or meter problem, call your TDU (Oncor, CenterPoint, AEP Texas or TNMP) directly, not Green Mountain.
Depends on your situation. At an average Texas household of 1,176 kWh/month, the Green Mountain premium adds roughly $14 to $35 per month versus a non-renewable fixed plan, or about $170 to $420 a year. A 6 kW rooftop array in Texas typically costs $100 to $150/month financed and offsets 70 to 90% of grid usage, plus it qualifies for federal IRS residential clean-energy credits. If you own a home with a suitable roof, the premium dollars often go further as part of a solar down payment. If you rent or the roof is unsuitable, RECs are the practical way to back renewable generation.
More U.S. states with energy choice
Same playbook, different utility. Pick another deregulated state to compare utilities, suppliers and switching rules.
