The Ministry of Energy says rooftop solar permits now finish within 7 days, and grid sell-back applications within 30 days (previously up to a year). The 500 MW extra purchase quota is open. Under the "Solar 1 million roofs" plan, state banks (Krungsri... no: Government Savings Bank and GHB) offer soft loans at 2–4% a year, repaid from the electricity bill savings, with no upfront payment for households. The article's example: a 5 kW system producing about 600 units a month, saving roughly 2,150–2,200 baht a month, with payback in 5–7 years. For a small business with a roof, this is worth checking now. Confirm the eligibility rules with the ministry or the bank, since the article does not state the business-specific terms.