Compare off-grid and shared energy systems

Are we buying bill credits, a shared service or a system able to supply specified loads without the wider grid?

Describe what the arrangement actually delivers. Separate a subscription’s financial benefit from electricity available during an outage. For a physical shared or off-grid system, assess resources, controls, operating responsibility, maintenance and failure arrangements as one system.

Evidence checked October 16, 2026 (America/Denver). Version 1.0. Desk review; no hands-on testing.

What this guide helps you do

For choosing questions, documentation and competent assessment. It does not create an off-grid design, a microgrid operating procedure, a utility agreement or a finding that a subscription program or particular offer is available.

Name the arrangement and the service boundary

Write where electricity is generated, which equipment or loads are served, who owns each component and how the household pays. A subscription to an off-site array, a building’s shared supply and a system operated independently of the utility grid are different arrangements. Record the claimed benefit in concrete terms: a bill credit, access to a particular service or operation of specified loads under stated conditions. Include the needs of renters and people who cannot install their own equipment. Do not let a label such as community, renewable or independent stand in for an actual service description.

Read an off-site subscription as a billing arrangement

DOE describes community-solar customers paying for a share of generation and receiving a utility bill credit. Ask for the fee, credit calculation, timing, remaining utility charges, contract period and termination or transfer terms. Compare actual total charges before and after the subscription on the same assumptions. National descriptions of savings and desirable protections are not a guarantee that every local offer has them. Ask the utility how the proposed program affects this account. A normal subscription does not demonstrate backup electricity at the home; require separate evidence of any claimed resilience service. Source: DOE community-solar basics.

Ask what makes a physical system island-capable

NLR describes a microgrid as controllable loads and energy resources able to connect to or disconnect from the grid. Its controls must manage power balance and the timing of connection changes. A collection of panels and batteries alone does not establish those functions. Ask a qualified designer to identify the actual service boundary, essential loads, starting and restoration arrangements, and operating limits. Request commissioning and test evidence for the intended mode. Do not operate switches or create an electrical island from a short online explanation. Source: NLR microgrid controls overview.

Evaluate the difficult operating period

For an off-grid or isolated arrangement, ask how supply meets demand during the period that is hardest for the actual site, not merely over an average year. DOE’s wind guide distinguishes connected, stand-alone and hybrid systems and the equipment around the generator. Have the assessor explain storage, other supply, demand reduction, maintenance access and recovery when a component fails. Identify fuel, parts, software, communications and specialist dependencies that remain. Record assumptions and limitations so the word independent does not conceal a new dependence on one irreplaceable component or supplier. Source: DOE Small Wind Guidebook.

Check the local offer and responsible authority

Colorado PUC’s inclusive community-solar page explains subscription credits and links uniform disclosure and discount-reporting forms. It also contains material about concluded 2026 pre-rulemaking activities and prospective rulemaking. Use it as a route to the responsible authority, not proof of the current stage, open enrollment or an automatic discount. Confirm the actual utility, governing program, approved documents and provider offer. If several homes will share physical infrastructure, obtain competent advice about applicable approvals, ownership, land access, metering and operating responsibilities before commitments are made. Source: Colorado inclusive community-solar navigator.

Make long-term responsibility part of the decision

For a physical shared arrangement, document who owns and insures equipment through the appropriate specialist routes, who has operating authority, and who pays for maintenance, replacements and reserve needs. Keep access, emergency contacts and service records available to authorized custodians. Decide how a new resident joins, a departing member exits and a failed service is handled. Ask who can continue the system if its original organizer leaves. For a subscription, retain the actual contract and a way to dispute an incorrect credit. Recheck the arrangement against real service and bills rather than the original presentation.

A pathway to practice

Identify the arrangement: Credits, shared supply, isolated loads
Verify the promised service: Bills or physical operating evidence
Assess dependencies: Controls, supply, care, recovery
Assign lasting responsibility: Authority, costs, records, successors

Resources and their limitations

DOE community-solar basics

Use it for: Understand an off-site subscription and the relationship between its fees and utility credits.

Access and cost: Public overview freely readable. Subscription fees, enrollment, exit terms and actual bill credits require a current written offer.

How to use it: Read How Does Community Solar Work and Consumer Protections. Ask the actual utility/provider about service area, credit timing and all charges.

Evaluation and limits: The overview’s benefits and recommended protections are not universal contract rights or guaranteed savings. A normal off-site subscription is not proof of backup electricity at the home. No project, state list or subscriber offer checked.

Alternatives: Actual utility tariffs and approved disclosures; rooftop assessment; reducing demand without a subscription.

Open DOE community-solar basics

NLR microgrid controls overview

Use it for: Identify what a claimed island-capable system must coordinate beyond simply owning solar panels.

Access and cost: Public research overview freely readable; no design tool run, engineering service retained or household system priced.

How to use it: Use the opening definition and control requirements to frame questions for a qualified designer about loads, storage, control, disconnection and restoration.

Evaluation and limits: Conceptual overview and selected control requirements reviewed; research projects and standards are not a certified household design. No commissioning, black-start, runtime or grid permission established.

Alternatives: Actual engineered design and utility interconnection process; a smaller standalone device arrangement.

Open NLR microgrid controls overview

Colorado inclusive community-solar navigator

Use it for: Locate Colorado’s program explanation and uniform subscriber-disclosure route.

Access and cost: Public page freely readable; actual subscription availability, discounts, eligibility and charges not verified.

How to use it: Start with the program explanation and Uniform Disclosure form link. Confirm the current proceeding, applicable program and offer with the responsible utility/provider.

Evaluation and limits: The page mixes concluded 2026 pre-rulemaking material with disclosure links. Current rulemaking stage, statute, final rules, forms and specific offers were not fully audited. No claim that enrollment is open or a discount is guaranteed.

Alternatives: The responsible electric utility and current approved disclosures; DOE’s general explanation.

Open Colorado inclusive community-solar navigator

DOE Small Wind Guidebook

Use it for: Screen whether small wind merits a site-specific assessment, and separate annual energy from a turbine’s rated power.

Access and cost: Public guide freely readable. Measurement, engineering, permits, equipment, installation and service can cost money; no quote obtained.

How to use it: Start with energy needs, wind-resource assessment, siting and annual energy output. Ask a qualified assessor about the actual site and full system.

Evaluation and limits: Scoped review of assessment and system-dependency sections, not a complete design audit. Old costs, incentives, battery prescriptions and numerical tower rules are not adopted. No site, model or measured output verified.

Alternatives: PVWatts for a qualified grid-connected solar estimate; efficiency improvements; competent local assessment.

Open DOE Small Wind Guidebook

Checklist

Billing, physical supply and service boundary distinguished
All fees, credit timing, remaining charges and exit terms obtained
Islanding or off-grid claims supported by qualified design/test evidence
Difficult operating periods and remaining dependencies assessed
Actual local program, utility and approvals confirmed
Ownership, maintenance, replacement and successor roles recorded

From the Whole Earth registry to current practice

Fall 1968 Village Technology (PDF page 20) presents small-group tools and technical information. Spring 1969 Electricity From the Wind (PDF page 38, printed 36) asks about actual user experience. Both were visually reviewed. The editorial connection is to capability, maintenance and evidence. Contemporary utility subscriptions and microgrid controls are separately sourced; historical diagrams do not establish an approved system.

Whole Earth Fall 1968 archive edition; Whole Earth Spring 1969 archive edition

Sources and review notes

No subscription, tariff, final Colorado rule, physical system, operating test, utility permission or project governance instrument was evaluated. DOE’s general consumer protections are not universal rights. No insurance research was repeated; specialized overlap routes to the existing institutional libraries.