Invinity Energy Systems

IES.L

Electrical Equipment & Parts · Industrials

Price

23.90 GBp

-0.30 (-1.24%)

Market Cap

£136.1M

Exchange

London Stock Exchange

Winston Score

Winston is worried

Below-average fundamentals — multiple weak pillars.

Data as of Aug 23, 2026 · filings through Dec 31, 2025

How the score breaks down

Quality

Weak

Growth

Strong

Cash Flow

Weak

Stability

Data not available

Valuation

Data not available

Track this stock — start free trial

Share count rising — dilution

+436.8% over 4y

The company has issued more shares over this period, which dilutes each existing shareholder’s stake.

Diluted shares outstanding: 89.9M (2021) → 482.7M (2025)

Winston Score History

The full picture

Invinity Energy Systems makes large batteries designed to store electricity from renewable energy sources like solar and wind farms. Its main product is the vanadium flow battery, which can store and release power for many hours at a time. The company sells these systems to utilities, grid operators, and commercial customers who need reliable, long-duration energy storage.

Invinity earns revenue by selling battery systems and providing ongoing service contracts. It operates primarily in the UK, North America, and parts of Asia, and is a small company still in an early stage of growth. Vanadium flow batteries can be recharged thousands of times without significant degradation, which is a technical advantage over lithium-ion alternatives for long-duration storage — but the company is currently losing money on every sale, and its main challenge is scaling up production enough to bring costs down and reach profitability before it needs to raise more capital.

Growth Profile

For growth stock investors

When traditional metrics don't capture the full picture, these are the signals growth stock investors use instead.

Revenue Growth

+134.6% YoY

YoY Growth Rate

Strong revenue growth

EPS Growth

-36.5% YoY

YoY Growth Rate

Earnings declining

R&D Spend

£2M/ year

↓ Declining (-26% vs prior year)

21.8% of revenue

21.8x the sector average (1%)

R&D spend declining — could signal cost-cutting or efficiency

Insider Activity

34.5%ownership

↑ Rising

Insiders increasing their stake — aligned with shareholders

Cash Runway

~4 months

£29M cash & investments

Quarterly Free Cash Flow

↓ Burn rate worsening

Short runway — potential dilution ahead through share issuance

Strong grower

Invinity Energy Systems is growing revenue at 135% year-over-year. The Winston Score penalises unprofitable companies, but revenue at this pace tells a different story — this is a company still in "build mode."

The Winston Score above measures business quality today. Growth stocks often score lower because they invest in the future rather than maximising current profits. These metrics show what matters most for evaluating that future.

Score breakdown

Every number that matters to educated investors.

Each metric is explained in plain language so you know exactly what you're looking at. Start your free trial now.

Quality

Profit per sale

Gross Margin

-19.3%

Thin — -19.3% gross margin

Profit after running costs

Operating Margin

-167.4%

Losing money on operations — -167.4%

Return on the money invested

ROCE

-38.0%

Weak — -38.0% return on capital

Negative ROIC means the business is losing money on every dollar invested in it.

Full breakdown available with your free trial

See every metric, trend, and what it means for this stock.

Try free

Growth

Sales growth

Sales YoY

+63.2%

Fast-growing sales (+63.2% YoY)

Profit growth

EPS YoY

N/A

—

Data not available

How steady the profit is

EPS Consistency

7/8 quarters

Every recent quarter grew earnings vs last year

Full breakdown available with your free trial

See every metric, trend, and what it means for this stock.

Try free

Cash Flow

Profit that turns into cash

Cash Conversion

N/A

—

Data not available

Spare cash per sale

FCF Margin

-399.1%

Burning cash (-399.1%)

Free cash flow is negative. They are burning cash, not generating it.

Full breakdown available with your free trial

See every metric, trend, and what it means for this stock.

Try free

Stability

What it owes vs what it owns

Debt / Equity

N/A

Data not available

Covers its interest

Interest Cover

N/A

Data not available

Full breakdown available with your free trial

See every metric, trend, and what it means for this stock.

Try free

Valuation

Price vs profit

P/E Ratio (TTM)

N/M

—

Negative earnings — P/E not meaningful

Cheaper or dearer next year

P/E vs Forward

N/A

not available

Data not available

Full breakdown available with your free trial

See every metric, trend, and what it means for this stock.

Try free

Dividends

Not applicable for this business.

🔒 See full fundamentals and if they are improving or declining — click here for your free trial now.

Start free trial