How to Do Due Diligence on a Solar Investment Platform
By Hardik BhatiaPublishedWhen you invest in a publicly traded stock, an army of analysts, auditors, regulators, and rating agencies has already scrutinized the company. Quarterly earnings are public. Risk factors are disclosed in SEC filings. Analyst coverage provides independent perspective. The infrastructure of public market oversight does much of the due diligence for you.
Private offerings are different. When you invest in a fractional solar project under SEC Regulation D, you are entering a private placement where the level of independent scrutiny is significantly lower. There is no analyst coverage. There are no quarterly earnings calls. The SEC does not review or approve the offering - it simply accepts the Form D filing. The burden of evaluating the investment falls on you.
This is not a flaw in the system. It is the system. Accredited investors are presumed to have the financial sophistication and resources to evaluate private offerings independently. The question is whether you actually do the evaluation - or whether you skip it because the projected returns look attractive.
This checklist is designed to make that evaluation systematic. It covers 31 items across six categories: legal and regulatory standing, PPA and off-taker quality, project fundamentals, operations and insurance, fees and distributions, and exit terms. Each item includes what to look for, where to find it, and what constitutes a red flag.
How Do You Verify the Platform's Legal and Regulatory Standing?
Before evaluating any solar project, verify that the platform itself is legitimate, properly registered, and operating within the law.
1. Check the Form D filing on SEC EDGAR. Every Reg D offering must file a Form D notice with the SEC. Search the SEC's EDGAR database (sec.gov/cgi-bin/browse-edgar) by the issuer's name or CIK number. Confirm the entity name, state of organization, offering type (506(b) or 506(c)), total amount offered, and amount sold. For a Regulation D offering, the absence of a Form D filing should be treated as a serious warning sign that warrants further investigation.
2. Confirm the entity is a registered LLC or corporation. For Delaware LLCs, search the Delaware Division of Corporations website (icis.corp.delaware.gov). Verify the entity name, formation date, and status (Good Standing). If the entity is not in good standing or does not exist, do not invest.
3. Review the Private Placement Memorandum (PPM). The PPM is the legal disclosure document for the offering. It should clearly describe the investment structure, the specific solar project, the PPA terms, the risk factors, the fee schedule, the distribution mechanics, and investor rights. Read it completely. A PPM that is vague on any of these points is a red flag.
4. Research the management team. Identify the principals behind the platform - their names, professional backgrounds, track records in solar or energy investment, and any prior regulatory actions. Search FINRA BrokerCheck, the SEC's Investment Adviser Public Disclosure database, and general news/litigation databases. An anonymous or unverifiable management team is a disqualifying signal.
5. Check for SEC enforcement actions. Search the SEC's enforcement actions database for any actions involving the platform, its management, or related entities. Also check state-level securities regulators. Prior securities violations are a serious red flag.
6. Evaluate operating history. How long has the platform been operating? How many projects has it completed? What is the track record of actual distributions to investors? A platform with no operating history is not automatically disqualifying - every platform starts somewhere - it means you are taking additional risk compared to one with a documented performance record.
For a deeper understanding of the SEC registration framework, see our guide: How Fractional Solar Investment Works: A Guide for US Investors.
How Do You Evaluate the PPA and Off-Taker?
The Power Purchase Agreement is the foundation of every solar project's economics. If the PPA is weak, nothing else matters.
7. Confirm the PPA exists and is signed. This sounds basic, but some offerings present projected returns based on expected PPAs that have not yet been executed. A signed PPA is fundamentally different from a projected PPA. Verify the contract status.
8. Check the PPA duration. Longer PPAs (15-25 years) provide more revenue certainty. Shorter PPAs (5-10 years) carry re-contracting risk earlier in the investment. The PPA duration should be clearly disclosed in the PPM.
9. Examine the tariff rate and escalation clause. What is the price per unit of electricity? Is there an annual escalation? What is the escalation rate? Many Indian C&I solar PPAs include annual escalation provisions, often in the low single digits, though structures vary by project and counterparty. No escalation means the real value of the tariff erodes with inflation over time.
10. Identify the off-taker and assess their creditworthiness. Who is buying the electricity? Is it a state-owned distribution company (DISCOM), a large industrial manufacturer, a commercial business, or a government institution? A creditworthy C&I buyer with a direct economic incentive to maintain the contract is a stronger counterparty than a financially stressed DISCOM. If the platform will not disclose the off-taker's identity, that is a red flag.
11. Review termination and transfer provisions. What happens if the off-taker wants to terminate early? What are the penalty provisions? Does the PPA include a transfer clause at expiry - and if so, at what price? If ownership transfers to the off-taker for nominal value (₹1 or depreciated book value) at PPA expiry, the financial projections should reflect zero terminal value.
12. Understand the DISCOM vs C&I distinction. DISCOM PPAs and C&I open access PPAs carry fundamentally different risk profiles. DISCOM PPAs involve government counterparties with potential payment delays and political renegotiation risk. C&I PPAs involve private buyers with direct economic incentives. Know which type you are investing in.
For a detailed analysis of PPA counterparty risk and the Andhra Pradesh precedent, see: Solar Investment Risks: What Every Accredited Investor Should Know.
How Do You Assess the Solar Project Itself?
The underlying solar asset determines whether the revenue projections in the PPM are realistic.
13. Verify the site location and solar resource. Where is the project located? What is the Global Horizontal Irradiance (GHI) at the site? India ranges from 4 to 7 kWh/m²/day, with western and southern states generally offering stronger irradiance. A project in Rajasthan will have a different generation profile than one in Meghalaya. The site's solar resource should be documented with independent data, not just the developer's assertion.
14. Check the installed capacity (DC and AC). What is the total DC capacity (panel output) and AC capacity (inverter output)? What is the DC/AC ratio? A ratio of 1.1 to 1.4 is standard. Significantly higher ratios may indicate clipping losses; significantly lower ratios suggest underutilized inverter capacity.
15. Identify the panel manufacturer and tier rating. Are the panels from a Tier 1 manufacturer (as classified by BloombergNEF)? BloombergNEF Tier 1 status indicates that a manufacturer has supplied modules to projects financed by major banks and institutions. It is often used as a proxy for bankability, but it is not a direct measure of product quality. Panels from unrated or unknown manufacturers carry higher performance and warranty risk.
16. Check the inverter brand and warranty. Inverters are the most failure-prone component in a solar plant. String inverters typically carry 10-12 year warranties; microinverters and some central inverters carry up to 25 years. What brand is being used? What is the warranty duration? Who bears the cost of replacement if the inverter fails after the warranty period?
17. Examine the generation projections. Are the projected energy generation figures based on P50 (median) or P90 (conservative, 90% confidence) estimates? If the financial model uses P50 estimates, the projected generation represents a median outcome, meaning actual energy production may be above or below the forecast with roughly equal probability. If P90, the projections are more conservative and more likely to be met. Always ask which probability level the projections are based on. If the platform does not disclose this, treat the projections with skepticism.
18. Verify the EPC contractor's track record. Who built the plant? How many megawatts have they installed? Do they have experience with projects of this size and technology? An inexperienced EPC contractor increases construction and commissioning risk.
19. Confirm grid connection status. Is the project already connected to the grid, or is grid connection pending? A project that is already operational and grid-connected is lower risk than one still awaiting connectivity approvals.
How Do You Evaluate Operations, Monitoring, and Insurance?
A solar plant is only as good as its ongoing management. Strong fundamentals can be eroded by poor operations.
20. Identify the O&M contractor and review SLA terms. Who is responsible for maintaining the plant? What are the contractual performance targets (e.g., minimum availability, response time for fault resolution)? Is the O&M contract with an independent third party, or is the platform self-performing? Self-performing O&M is not inherently worse, but it does create a potential conflict of interest that should be disclosed. In cases, in house makes it better to address timely issues.
21. Check for real-time monitoring access. Does the platform provide investors with access to a live dashboard showing actual generation data, inverter performance, and revenue tracking? Monitoring transparency is one of the clearest signals of platform quality. A platform that cannot or will not provide real-time project data should be treated with caution. You should be able to verify that the plant is producing what was projected - not take it on faith.
22. Review insurance coverage. The PPM should disclose the insurance policies in place for the solar asset. Look for comprehensive all-risk property insurance covering natural disasters, fire, and equipment failure, business interruption insurance that compensates for lost revenue during downtime, third-party liability coverage, and equipment warranty insurance or manufacturer-backed warranties. If insurance coverage is not disclosed in the PPM or is unavailable upon request, that is a red flag.
23. Understand inverter replacement provisions. Inverters may require major refurbishment or replacement during the life of a long-duration solar project, depending on technology, operating conditions, and maintenance practices. Who bears the cost? Is there a reserve fund set aside for inverter replacement, or does the cost come out of investor distributions? The answer affects your effective returns in later years of the investment.
24. Ask about decommissioning reserves. Is the SPV required to set aside funds for eventual plant decommissioning? If not, decommissioning costs at end of term could consume a meaningful portion of the final distribution.
How Do You Scrutinize Fees, Distributions, and Exit Terms?
Fees and exit terms are where investor-unfriendly structures hide. Read the fine print.
25. Understand the full fee structure. What is the annual management fee (expressed as a percentage of assets or revenue)? Is there a performance fee or carried interest? Are there acquisition fees, disposition fees, or administration fees? All fees should be clearly disclosed in the PPM. If you have to ask to find the fees, the disclosure is inadequate.
26. Review the distribution waterfall. How are project revenues distributed? What gets paid first - debt service, operating expenses, management fees, or investor distributions? The priority of payments determines how much reaches you after all other obligations are met. A waterfall where management fees are paid before investor distributions (above a preferred return threshold) is less investor-friendly than one where investors receive a preferred return first.
27. Confirm payout frequency and currency mechanics. How often are distributions made - monthly, quarterly, annually? For cross-border investments, how is INR revenue converted to USD? What exchange rate mechanism is used? Is there any currency hedging in place, or do investors bear the full INR/USD exposure? These details affect your effective return.
28. Examine exit provisions in the Operating Agreement. What happens at PPA expiry? Does the manager have unilateral authority to renew, sell, or decommission? Do investors get a vote on major exit decisions? Is there a defined wind-down timeline? What are the conditions under which the manager can extend the investment without investor consent? These provisions are covered in the LLC Operating Agreement, which should be appended to or referenced in the PPM.
29. Check manager discretion limits. What decisions can the management team make without investor approval? Are there caps on capital expenditures, related-party transactions, or fee increases? Broad, unchecked manager discretion is a governance risk - particularly for a long-duration investment where the manager's interests may diverge from investors' over time.
30. Review related-party transactions. Are the EPC contractor, O&M provider, project seller, or other service providers affiliated with the platform or sponsor? Related-party arrangements are not inherently problematic, but they should be clearly disclosed and priced on arm's-length terms. Investors should understand how fees flow between affiliated entities and whether conflicts of interest exist. If the platform is simultaneously the investment manager, the EPC contractor, and the O&M provider, the potential for self-dealing is elevated-— and the disclosure standards should be correspondingly higher.
31. Ask about early exit options. Is there any mechanism for exiting before the PPA expires? Can membership units be transferred to other accredited investors with manager approval? Is there a buyback provision at the manager's discretion? Most fractional solar offerings have limited or no early exit options - but the terms should be explicitly disclosed rather than left ambiguous.
For a detailed analysis of exit scenarios and how proceeds flow at PPA expiry, see: What Happens When a Solar PPA Expires? Exit Mechanics Explained.
What Are the Biggest Red Flags That Should Stop You from Investing?
Not every concern is a red flag. Some items on this checklist will have imperfect answers — that is the nature of private investments. But certain signals should make you walk away entirely.
No SEC filing. If the issuer has not filed a Form D with the SEC for a Reg D offering, the offering may not be in compliance with federal securities law. This should be treated as a serious warning sign that warrants further investigation before proceeding.
Guaranteed return language. It is illegal for issuers of private securities to guarantee returns. If a platform promises "guaranteed 12% returns" or "risk-free income," it is either violating securities law or misrepresenting the investment. Either way, do not invest.
No identifiable management team. If you cannot find the names, backgrounds, and track records of the people managing your money, you have no basis for trust. Do not invest.
Pressure to invest quickly. Legitimate offerings do not create artificial urgency. If you are told "this opportunity closes in 48 hours" or "only 3 units left," treat it as a sales tactic, not a genuine constraint. Take the time you need to complete your due diligence.
No PPM or Operating Agreement. These are the foundational legal documents for any private offering. If the platform cannot or will not provide them before you invest, do not invest.
No project-level data. If the platform cannot tell you where the solar project is located, what the PPA terms are, who the off-taker is, or what the generation projections are, you are not investing in a solar project — you are investing in a promise. Do not invest.
Refusal to answer questions. The single most reliable red flag. A legitimate platform will welcome investor questions — about structure, risks, fees, and exit terms. If your questions are deflected, minimized, or met with irritation, that tells you everything you need to know about how the platform will treat you after you invest.
Frequently Asked Questions
How long should due diligence take for a fractional solar investment? For a first-time investor, thorough due diligence typically takes one to two weeks - enough time to review the PPM, verify SEC filings, research the management team, evaluate the PPA terms, and ask questions. Subsequent investments in the same platform may require less time if the structure and team are consistent. Do not compress your due diligence timeline because of artificial urgency from the platform.
Can I hire someone to do due diligence for me? Yes. A securities attorney can review the PPM and Operating Agreement for legal risks. A CPA or tax advisor can evaluate the financial projections and tax implications. An independent solar engineer can assess the project's technical assumptions (irradiance, CUF, degradation). For larger investments, this professional review is worth the cost. For smaller allocations, the checklist in this blog covers the essential items you can evaluate independently.
What questions should I ask the platform directly? Start with these: What is the off-taker's identity and credit profile? What probability level (P50 or P90) are the generation projections based on? What is the full fee schedule, including any fees not prominently disclosed in the PPM? What are the specific exit provisions — can you extend the investment without my consent? What happens if the off-taker defaults? Can I see the real-time monitoring dashboard for existing projects? A platform's willingness to answer these questions thoroughly and transparently is itself a due diligence signal.
About Sustvest
SustVest LLC is a Delaware-registered fractional solar investment platform offering SEC Regulation D 506(c) compliant investment opportunities in Indian solar energy projects. Through its US entity structure, Sustvest enables accredited investors and NRIs to own membership interests (units) in operating solar projects backed by long-term Power Purchase Agreements. Each project is held in a separate Indian SPV, with SustVest LLC owning 100% of each SPV. Investors receive proportional monthly cash distributions in USD, with a minimum investment of $500 and target returns of 10–14% XIRR. Project details, SEC filings, and real-time generation data are available at sustvest.com.
This content is for informational purposes only and does not constitute an offer to sell or a solicitation of an offer to buy any securities. This checklist is educational and does not constitute legal, financial, or investment advice. Investments in private offerings under SEC Regulation D are speculative, illiquid, and involve a high degree of risk, including the potential loss of the entire investment. Fractional solar investments are available only to verified accredited investors as defined under SEC Rule 501(a). Past performance is not indicative of future results. Prospective investors should carefully review the Private Placement Memorandum (PPM) and LLC Operating Agreement, and consult with their own legal, tax, and financial advisors before making any investment decision. SustVest LLC does not provide investment, legal, or tax advice.
Sources:
SEC.gov — EDGAR database for Form D filings (sec.gov/cgi-bin/browse-edgar)
SEC.gov — Rule 506(b) and 506(c) of Regulation D; Form D filing requirements
Delaware Division of Corporations — Entity search (icis.corp.delaware.gov)
FINRA — BrokerCheck for individual and firm background checks (brokercheck.finra.org)
SEC.gov — Investment Adviser Public Disclosure database (adviserinfo.sec.gov)
SEC.gov — Enforcement Actions database (sec.gov/litigation)
BloombergNEF — Tier 1 solar module manufacturer classification: based on bankability (modules supplied to projects financed by 6+ non-recourse lenders in past 2 years), updated quarterly
NREL — Solar modules typically degrade at roughly 0.5% per year on average, though actual rates vary by technology, climate, and operating conditions
MNRE / Global Solar Atlas — India solar irradiance: 4–7 kWh/m²/day across most of the country
FTI Consulting / DNV — "Due Diligence Considerations for Investing in the Energy Transition" (September 2024)
IEA PVPS — Technical due diligence frameworks for solar project investment
Internal links (add when publishing):