Thailand could meet its growing power needs at a far more affordable cost by betting big on homegrown solar and energy storage, says a new report from global energy think tank Ember.

Looking ahead to 2037, Ember’s modeling shows that nearly doubling Thailand’s planned solar capacity and boosting battery storage by 60% could save around US$1.8 billion in electricity-generation costs while cutting 147 million tonnes of CO2.

Although this path would require slightly more upfront investment, at about US$168 billion compared with US$153 billion under the government’s current plan, the payoff comes from lower operating costs, mainly due to less reliance on natural gas. That means US$16 billion in fuel savings and 11% less natural gas use overall — roughly 1.8 trillion cubic feet avoided by 2037, or nearly twice what Thailand’s power sector consumed in 2024.

Fossil fuels currently still supply more than 80% of Thailand’s power, with natural gas making up about 68%. That dependence is growing riskier as much of the country’s liquefied natural gas (LNG) is imported and expected to reach nearly 60% by 2035. This reliance has already hit consumers, with business tariffs jumping to THB5.69 per kilowatt-hour (kWh) in early 2023 amid global LNG price spikes. “Solar, coupled with battery storage, represents the optimal pathway,” says Ember energy analyst Lam Pham.

Powering EVs, data centers, and the next wave of growth

Thailand’s next growth engines, comprising electric vehicles and data centers, will need enormous amounts of electricity. EVs alone could account for about 20% of demand by 2037, while data centers could add another 10 terawatt-hours (TWh).

Even under tougher conditions than the government’s draft power plan, Ember’s scenario keeps the grid reliable without building the extra gas plants previously planned for the mid-2030s. Their model adds roughly 32 gigawatts (GW) of new solar and 6 GW or 15 gigawatt-hours (GWh) of batteries by 2037 to handle demand, particularly in the evenings when solar drops off.

They also recommend moving faster by getting large-scale battery storage online by 2027 (five years earlier than planned) to help smooth day-night power swings and keep a 15% reserve margin. Additional pumped-storage hydro capacity (about 3.5 GW by 2037) would further strengthen grid flexibility.

What Thailand should focus on next

To make the most of these opportunities, Ember argues, solar and storage need to become the backbone of Thailand’s power system. Gas and coal should meanwhile shift to backup roles, used mainly during shortfalls, to avoid wasting money on plants that might later sit idle.

The report urges planners to move beyond rigid capacity targets and instead measure reliability hour by hour, ensuring renewables can handle peak demand. It also cautions against large wind investments for now, noting that Thailand’s relatively low wind speeds make big resource-intensive projects costly compared with solar. Imported hydropower from Laos, though not without environmental and social risks, could help fill gaps more affordably.

Better forecasting will also matter. As EVs and data centers reshape energy demand, tools such as smart charging, time-of-use rates, and vehicle-to-grid programs could ease pressure on the grid while supporting Thailand’s 30@30 EV goal.

In the long run, the report concludes, scaling up solar and storage isn’t just about cleaner energy but providing the most reliable way to power Thailand’s next era of growth, while cutting costs and reducing dependence on energy imports.

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