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Green Mountain Energy
NRG Energy (NYSE: NRG)
VS
Pennywise Power logo
Pennywise Power
NRG Energy (NYSE: NRG)

Green Mountain Energy vs Pennywise Power

Complaint Comparison

PUCT Data • Jul-Dec 2025

Green Mountain Energy

2.7per 10k
Below avg
Top: Billing

Pennywise Power

7.1per 10k
Above avg
Top: Billing

Green Mountain Energy has 4.4 fewer complaints per 10k customers

Trust & Reputation

External ratings comparison

Source
Green Mountain Energy
Pennywise Power
BBB Rating
A+
Not Accredited
View Profile
Winner
Not Rated
Not Accredited
View Profile
Google Reviews
4.0
3.7K+ reviews
4.0
800+ reviews
Trustpilot
2.8
Poor
3 reviews (limited)
View Profile
No data
Trust Score(weighted)
4.5
out of 5.0
Winner
4.0
out of 5.0

Trust Score is a weighted average: Google (40%), BBB (35%), Trustpilot (25%)

The Verdict

Choose Green Mountain Energy if...
  • Environmental impact justifies the 20-30% premium
  • You want authentic renewable sourcing, not marketing green-wash
  • 27 years of environmental track record matters
  • You'd pay extra for wind/solar farm contracts over RECs
Choose Pennywise Power if...
  • You want NRG stability at budget prices
  • Green energy is a nice-to-have, not a requirement
  • Basic fixed-rate electricity is all you need
  • You'd rather save $200-$300/year than fund renewables

Category Breakdown

Price
Pennywise Power

Pennywise saves 20-30% over Green Mountain's premium

Green Energy
Green Mountain Energy

Green Mountain is 100% renewable; Pennywise offers none

Stability
Tie

Both owned by NRG Energy--identical Fortune 500 backing

Plan Variety
Green Mountain Energy

Green Mountain has more contract options

Simplicity
Pennywise Power

Pennywise has no complexity--just basic fixed rates

Side-by-Side Comparison

Feature Green Mountain Energy Pennywise Power
Parent Company NRG Energy NRG Energy
Years in Texas 27+ 18+
Service Areas Oncor, CenterPoint, AEP, TNMP Oncor, CenterPoint, AEP, TNMP
Fixed-Rate Plans
Variable Plans
Green Energy 100% (all plans)
Prepaid Options
Contract Lengths 1-36 months 1-24 months
Deposit Required Conditional Conditional
Credit Check

At a Glance

FactorGreen Mountain EnergyPennywise Power
Best ForEnvironmental puristsBudget-conscious shoppers
Price LevelPremium (15-25% above average)Budget
Years in Texas27+18+
Green Energy100% (all plans)None
Parent CompanyNRG EnergyNRG Energy

Bottom Line: Same corporate parent, opposite strategies. Green Mountain charges premium rates for authentic renewable energy. Pennywise strips everything away for budget pricing. Both have identical NRG stability—the only difference is what your money funds.


The Short Answer

NRG owns both companies. You’re choosing between the same corporation’s premium environmental brand and budget no-frills brand.

Green Mountain exists to serve customers who’ll pay 20-30% more for renewable energy credibility. Direct wind/solar farm contracts. 27 years of environmental focus. The premium is real, but so is the renewable sourcing.

Pennywise exists to serve customers who see through brand taxes. No green energy, no rewards, no marketing—just basic fixed rates at budget prices. NRG stability without NRG premiums.

The NRG Family Tree

Understanding who owns what:

NRG Energy owns:

  • Green Mountain Energy (renewable premium)
  • Reliant Energy (rewards premium)
  • Cirro Energy (green-included mid-tier)
  • Pennywise Power (budget fixed-rate)
  • Discount Power (budget prepaid)

When you’re comparing Green Mountain to Pennywise, you’re comparing one company against itself. The stability is identical. The environmental sourcing is not.

The Price Math

On a typical 1,200 kWh/month household:

Green Mountain: ~14-16¢/kWh = ~$180/month Pennywise: ~10-12¢/kWh = ~$144/month Annual difference: $250-$400

That’s the cost of renewable energy sourcing. Green Mountain contracts directly with Texas wind and solar farms. Pennywise buys standard grid electricity.

The Environmental Difference

Green Mountain’s approach:

  • 100% renewable electricity—no exceptions
  • Contracts directly with Texas wind and solar farms
  • Your money funds actual renewable infrastructure
  • 27 years of track record since before deregulation
  • Transparent sourcing—they publish which farms supply power

Pennywise’s approach:

  • Standard grid electricity
  • No green options available
  • No environmental claims or pretense
  • No premium pricing for features you might not want

Most providers’ “green plans” buy Renewable Energy Certificates (RECs)—paper credits that theoretically offset conventional power. Green Mountain goes beyond RECs with direct sourcing contracts. That’s what you’re paying for.

What Both Companies Share

Since NRG owns both:

  • Identical stability: Fortune 500 backing, $70B+ parent company
  • Same service areas: Oncor, CenterPoint, AEP, TNMP
  • Similar enrollment: Credit checks, conditional deposits
  • Mid-tier customer service: Neither has Reliant’s app quality or 24/7 support

The only real differences are:

  1. Green energy vs standard electricity
  2. Premium pricing vs budget pricing
  3. Environmental credibility vs cost savings

Plan Options

Green Mountain offers:

  • Fixed-rate (12-36 months)
  • Variable-rate
  • All plans 100% renewable
  • Staff who understand renewable energy sourcing

Pennywise offers:

  • Fixed-rate (12-24 months)
  • Variable-rate
  • No green options
  • No frills

Neither offers prepaid, free nights, or specialty plans. If you need those features, both companies lose to Reliant (same NRG parent) by default.

The Verdict

Choose Green Mountain if:

  • Environmental impact is your genuine priority
  • You’re willing to pay $250-$400/year for renewable credibility
  • Authentic wind/solar sourcing matters more than REC offsets
  • 27 years of environmental focus means something to you
  • You want green energy from a company that’s only ever sold green energy

Choose Pennywise if:

  • You want NRG stability without paying green premiums
  • $250-$400/year in savings matters more than renewable sourcing
  • Basic fixed-rate electricity is all you need
  • Green energy is a nice-to-have you can skip
  • You’d rather donate to environmental causes directly with your savings

The honest take: This is a values question, not a quality question. Both companies deliver electricity reliably with identical NRG backing. Green Mountain’s environmental credentials are legitimate—probably the most authentic in Texas. But if renewable energy isn’t a priority for you, Pennywise delivers the same stability at budget prices.

Neither choice is wrong. They serve different values.

Company Profiles

Best-For Categories

Company Snapshots

Green Mountain Energy

Parent Company
NRG Energy (NYSE: NRG)
Years in Texas
27+
Headquarters
Austin, Texas
Deposit Required
conditional
Read full Green Mountain Energy review →

Pennywise Power

Parent Company
NRG Energy (NYSE: NRG)
Years in Texas
18+
Headquarters
Houston, Texas
Deposit Required
conditional
Read full Pennywise Power review →

"I like that it searched multiple companies for me. So I don't have to search one by one. Saves time."

— Lacy L., Texas

See Current Rates

Compare current plans from both companies.

Still deciding? Call (877) 418-2140 — Local Texans

Frequently Asked Questions

Q: When should I choose Green Mountain Energy over Pennywise Power?
A:

Environmental impact justifies the 20-30% premium. You want authentic renewable sourcing, not marketing green-wash. 27 years of environmental track record matters. You'd pay extra for wind/solar farm contracts over RECs.

Q: When should I choose Pennywise Power over Green Mountain Energy?
A:

You want NRG stability at budget prices. Green energy is a nice-to-have, not a requirement. Basic fixed-rate electricity is all you need. You'd rather save $200-$300/year than fund renewables.

Q: What is the main difference between Green Mountain Energy and Pennywise Power?
A:

Green Mountain Energy wins on green energy, plan variety. Pennywise Power wins on price, simplicity. Both deliver identical electricity through the same wires—the difference is pricing structure, customer service, and plan options.