AES vs FSLR: Which Is the Better Buy in 2026?
Last updated October 2026
Short answer
FSLR is the larger of the two ($18.55B market cap): the incumbent the market prices for continued execution (7.33x forward earnings, beta 1.79). AES is the smaller challenger ($10.66B), cheaper on forward earnings (6.30x): more room to run, but more to prove. The real question is which set of drivers you believe, and whether owning one (or both) leaves you over-concentrated.
AES vs FSLR: the tie-breaker metrics
Same yardstick, side by side (as of October 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.
| Metric | AES | FSLR | What it tells you |
|---|---|---|---|
| Market cap | $10.66B | $18.55B | Size. The larger name is the incumbent; the smaller has more room to grow and more to prove. |
| Forward P/E | 6.30 | 7.33 | Valuation on next year's expected earnings, the same yardstick for both. Lower is cheaper for that growth; higher means the market is paying up. |
| Trailing P/E | 5.60 | 10.64 | Valuation on the last 12 months. A big drop from trailing to forward means the market expects earnings to jump, so more growth is already in the price. |
| Beta | 0.95 | 1.79 | Volatility vs the market. Above 1 swings harder than the index; below 1 is steadier. Higher beta means bigger drawdowns to hold through. |
| Price vs 52-week range | 39% of range | 3% of range | Where today's price sits between the 52-week low and high. Near the high is momentum with less margin of safety; near the low is out of favor or a discount, depending on why. |
| Price / book | 2.16 | 1.80 | How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price. |
Reading it: AES is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.
Before you buy: how AES and FSLR affect your concentration
The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. AES and FSLR share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.
This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined AES and FSLR exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.
What does The AES Corporation (AES) do?
The AES Corporation is a global electricity company that operates across four segments: Renewables, Utilities, Energy Infrastructure, and New Energy Technologies. It owns or operates a generation fleet of roughly 34,740 megawatts spanning solar, wind, hydro, energy storage, gas, and legacy coal, and it distributes power to about 2.7 million utility customers. A key growth engine has been its renewables development pipeline, with a signed power purchase agreement backlog of about 12.6 gigawatts (around 5.6 GW under construction) as of March 2026, much of it tied to surging electricity demand from AI and cloud data centers. The company has been executing a coal exit while leaning into contracted clean generation and its regulated US utilities.
What does First Solar (FSLR) do?
First Solar is one of the largest solar panel manufacturers in the United States and the leading maker of thin-film solar modules. Unlike most competitors that use crystalline silicon, First Solar uses a cadmium telluride (CdTe) thin-film technology that it developed and manufactures at scale. This gives it a differentiated cost structure, strong performance in hot and humid climates, and a supply chain largely independent of the Chinese silicon ecosystem. The company sells utility-scale solar modules primarily to large developers and power producers building solar farms, mainly in the US, India, and other markets. First Solar makes money by manufacturing and selling these modules, and its US-based production qualifies for domestic manufacturing incentives. Headquartered in Tempe, Arizona, First Solar has expanded capacity aggressively across Ohio, Alabama, Louisiana, and India. It benefits from policy support for domestic clean energy manufacturing and from buyers seeking non-Chinese solar supply.
AES vs FSLR: how do they differ?
Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.
- AES drivers: Pending $15.00 cash acquisition; Renewables backlog and data-center demand.
- FSLR drivers: Domestic manufacturing incentives; Differentiated thin-film technology.
Which fits which kind of investor
A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The largest risk is deal-specific: a delay, regulatory block, or renegotiation of the $15.00 cash acquisition would remove the price support the stock currently enjoys. For FSLR, first Solar's fortunes are closely tied to policy, particularly US clean energy manufacturing incentives, which could change with political shifts.
AES or FSLR: which should you pick?
Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick AES if you believe its drivers more; FSLR if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the AES and FSLR guides.
AES vs FSLR: the full fundamentals
AES. AES trades at the $15.00 cash offer less a few cents, so headline multiples (a trailing P/E near 5.6 and a forward P/E near 6.3) matter less than the fixed deal price and the odds and timing of a close. With CFIUS, Ohio and European Commission approvals received by October 16, 2026, the spread has narrowed to about 0.2%. The high debt load, roughly $33 billion, is typical of a capital-intensive utility and is why the enterprise value (around $33 billion) is far larger than the equity value.
FSLR. First Solar is valued as a profitable, policy-advantaged solar manufacturer with substantial contracted backlog, and in October 2026 that valuation is low by its own standards: about 11 times trailing earnings, about 7.5 times forward estimates and about 7.4 times EBITDA after a roughly 36% fall in 2026. Investors are weighing strong margins and incentive support against uneven revenue, policy and trade risk, and higher rates. The October 29, 2026 report (consensus EPS near $4.70) will update the picture.
Headline figures (approximate, October 2026): AES shows share price / market cap ~$14.97 (Oct 16, 2026), ~$10.7B, acquisition price $15.00/share cash; spread ~3 cents (~0.2%), revenue (ttm) ~$13.1B; Q2 2026 ~$3.42B, net income (ttm) ~$1.9B, EPS ~$2.67; Q2 2026 EPS $0.44 vs ~$0.47 consensus; FSLR shows revenue (ttm) ~$5.4 billion (Q2 2026 down ~4% year over year), margins (ttm) ~44% gross, ~43% operating, ~32% net, net income (ttm) ~$1.75 billion, q2 2026 eps ~$3.92 vs ~$2.88 expected.
The bottom line: AES vs FSLR
AES and FSLR are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined AES and FSLR exposure against your real portfolio. It is not an investment adviser.
Wondering how AES or FSLR fits the portfolio you already own? Walnut is an AI investing app that connects your brokerage read-only and answers questions like that about your actual holdings: overlap, concentration, and how each position tracks the S&P 500. Compare the best AI portfolio analyzers or see the best AI investing apps in 2026.
Investing in The AES Corporation with AI
Connect the broker you already use and ask Walnut's AI how AES fits what you actually hold: whether you own it already through a fund, what it would do to your concentration, and how it has tracked the S&P 500. Read-only by default, and you approve anything before it reaches your broker.
FAQ
What is the difference between AES and FSLR?
+
The AES Corporation is a global electricity company that operates across four segments: Renewables, Utilities, Energy Infrastructure, and New Energy Technologies. First Solar is one of the largest solar panel manufacturers in the United States and the leading maker of thin-film solar modules. They show up together because they share investment themes, but they are different businesses, so the better fit depends on which thesis you are expressing.
Is AES or FSLR the better stock?
+
Neither is universally better. FSLR is the larger incumbent; AES is the smaller challenger and looks cheaper on forward earnings. Walnut is informational, not investment advice. Compare what each does, the tie-breaker metrics above, and the risks, then decide which fits your thesis and what you already own.
Which is cheaper, AES or FSLR?
+
On forward P/E (as of October 2026), AES trades at 6.30x and FSLR at 7.33x, so AES is the cheaper of the two on next year's expected earnings. A lower multiple is not automatically the better buy: a richer valuation can be justified by faster growth, and a lower one can reflect real risk. Weigh the multiple against how fast each business is compounding.
Should you own both AES and FSLR?
+
Because they share themes, owning both concentrates you in that theme. That can be intentional (a focused bet) or accidental (less diversification than it looks). Walnut can show your combined exposure across both, and whether adding either over-concentrates you, before you buy.
What are the risks of AES vs FSLR?
+
AES: The largest risk is deal-specific: a delay, regulatory block, or renegotiation of the $15.00 cash acquisition would remove the price support the stock currently enjoys. Several major approvals (CFIUS, Ohio state regulators and the European Commission) were in hand by October 16, 2026, but closing can still depend on other clearances across the many countries AES operates in, and the narrow spread of about 3 cents leaves holders with little cushion if anything slips. AES also carries substantial leverage, roughly $33 billion of debt against a market capitalization near $10.7 billion, which makes it sensitive to interest rates and refinancing conditions. International operations expose it to currency, political, and regulatory risk, and the ongoing coal exit and construction pipeline carry execution risk. If the deal broke, the shares could re-rate to a standalone value that may sit below the offer price; the stock traded as low as about $13.21 over the past year. FSLR: First Solar's fortunes are closely tied to policy, particularly US clean energy manufacturing incentives, which could change with political shifts. Solar is a cyclical, competitive industry with persistent pricing pressure from low-cost Chinese silicon panels. Oversupply, tariffs, and trade disputes can swing economics quickly. The company also faces technology risk, since its thin-film approach must keep pace with improving silicon efficiency. Interest rates affect utility-scale project economics, and large customers can delay or cancel projects. Manufacturing ramp execution, warranty issues, and module quality concerns are additional risks for a capital-intensive business that depends on flawless large-scale production. Revenue in the June 2026 quarter was down about 4% from a year earlier, and the shares fell about 36% in 2026 to mid-October; Morgan Stanley has flagged clean-tech names including First Solar as facing valuation pressure from higher rates.
Related comparisons
Browse all stock comparisons.
Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell AES or FSLR; figures are approximate and dated (as of October 2026). Verify current data before investing.