Financing the clean transition

Building a clean energy system is expensive up front and cheap to run. That single fact makes the transition a financing problem more than a technology problem. A solar farm, a grid upgrade or an electric bus fleet needs money today and pays it back over decades, so the price of that money decides whether the project happens at all.

The world is spending more on clean energy than ever, and about twice as much as it spends on fossil fuels, according to the International Energy Agency (IEA). But the money is unevenly spread. As explored in clean energy in emerging economies, most of it flows to advanced economies and China, while much of the developing world pays two to three times more to borrow for the same project.

What the global goals say

At the 2024 UN climate conference in Baku, governments agreed a new target: developed countries should take the lead in mobilising at least $300 billion a year for developing countries by 2035, as part of a broader aim of $1.3 trillion a year from all public and private sources. It replaced an earlier goal of $100 billion a year, which was first reported as met in 2022.

Earlier goal, 2020–25$100bn

Core goal, 2035$300bn

Wider goal, 2035$1,300bn

The $300bn goal is led by developed countries; the $1.3trn aim covers all sources, public and private. Source: UNFCCC, COP29 decision on the New Collective Quantified Goal

The numbers matter less than the gap they reveal. No plausible amount of aid alone can fund the transition. Most of the money must come from private investors, domestic budgets and development banks, with public funds used to make those flows cheaper and safer.

Where the money comes from

Source	What it does best	Limit
Domestic public budgets	Pays for grids, public transport and social protection	Squeezed by debt and competing needs
Private investors	Brings scale and speed to projects with steady returns	Avoids high-risk markets
Development banks	Lends long-term at low rates and absorbs risk	Capital is limited, processes can be slow
International climate finance	Grants and concessional loans for those who cannot borrow	Falls short of needs and often arrives as loans

Making public money go further

The most effective public finance does not replace private capital but unlocks it. Several tools are now in wider use:

• Guarantees and insurance cover the risks investors fear most, such as late payment by a utility or sudden regulatory change, so lenders accept lower rates.
• Blended finance places a layer of low-cost public money alongside private money, taking the first losses so commercial investors can join.
• Local-currency lending removes the danger that a falling currency makes dollar debts unaffordable.
• Debt-for-nature and debt-for-climate swaps let a government cut its debt in exchange for spending on conservation or resilience. Belize did this in 2021 and Ecuador in 2023.
• Green and sustainability-linked bonds raise money from investors who want a climate link, at a scale that has grown sharply.
• Reform of development banks can stretch their capital further, allowing them to lend more without new funds from shareholders.

Domestic policy sets the price of risk

Money follows predictability. Countries that publish clear long-term targets, run transparent auctions, pay their utilities’ bills on time and set stable rules for connecting to the grid attract cheaper finance, often from the same investors who avoid their neighbours. A government that makes the rules reliable is, in effect, offering a guarantee that costs the treasury very little.

Policy can also work against the transition. The International Monetary Fund estimates that explicit subsidies for fossil fuels, meaning direct support that lowers the price paid for them, topped $1 trillion worldwide in 2022 once the energy crisis hit. Money spent holding down the price of petrol and gas is money not available for grids, public transport or social protection, and it makes clean alternatives look expensive by comparison. Redirecting even part of it, while protecting poorer households through targeted payments, is one of the largest sources of finance available to governments that already exist.

Carbon pricing and clean-power auctions offer a second route. Both create a predictable revenue stream or a predictable cost that investors can plan around, and the proceeds can be used to fund investment or to compensate those who lose out.

What can go wrong

Loans counted as aid. A large share of international climate finance is lent rather than given. For countries already struggling with debt, adding more loans can leave them worse off. The United Nations Conference on Trade and Development estimates that more than 3 billion people live in countries that spend more on interest than on health or education.

Adaptation is neglected. Money flows readily to projects that earn a return, such as solar farms, and much less readily to those that protect people, such as flood defences or early warning. The UN Environment Programme estimates that adaptation needs in developing countries are many times larger than the finance they receive.

Poor accounting. Definitions of “climate finance” vary, and projects can be labelled green with only a loose link to climate goals. Without clear rules, it is hard to know how much money is new and how much is relabelled.

Leaving out the poorest. Capital tends to follow the safest returns. Low-income countries with the greatest needs can be passed over entirely.

The cheapest clean power in the world is useless if the project cannot find a lender.

What it implies

The financing challenge is solvable, because the underlying economics now work. The task is to lower the cost and risk of capital where it is highest, and to do so without piling debt onto the countries least able to carry it.

Three priorities stand out. First, expand low-cost, long-term lending, especially through development banks and guarantee schemes. Second, fix the debt problem, through restructuring, relief and swaps, so that governments have room to invest. Third, fund adaptation and the poorest countries deliberately, because markets will not.

Money, not technology, is now the binding constraint. Solving it is among the best-value tasks in the global economy, because every dollar that lowers the cost of capital in a developing country buys more clean energy than almost anywhere else.