The limits to various forms of energy are well-known. It's a bit more than I can describe in an HN comment, though Tom "Do the Math" Murphy has a good guide, index to his posts here: https://dothemath.ucsd.edu/post-index/ Heinberg himself has written of them in earlier books and articles.

Essentially humans have access to the fluxes of solar, geothermal, and tidal energy, and the stores of fossil fuels, nuclear fission from naturally occurring uranium and plutonium, and potentially nuclear fission from hydrogen plus a few other essential light isotopes and/or elements.

All other energy sources are either carriers (as with hydrogen as a combustion fuel), or derivative. Notably hydroelectric, wind, biomass, and wave energy are all derivatives of solar flux. (Fossil fuels are derivatives of past solar flux.)

Solar is the most tractable large-scale power source. The raw rate of incidence is about 1 kW/m^2 at Earth's surface. This is reduced by a number of considerations, including land area, spacing factors, panel efficiencies, and losses through conversion (DC/AC), transmission, and storage. The net potential is perhaps 5% of the total incident quantity. And there's the small factor that all other life on Earth also competes for this resource.

Hydro is proven but largely exploited, and has environmental consequences now increasingly recognised and often untenable.

Total wind and wave power (the latter is effectively nil) are small fractions of total solar power. Wind power is attractive principally as in places where it HAPPENS to be prevalent, the capital costs are low relative to energy returned.

Geothermal, while independent of solar, is a small fraction of the latter, and is already largely utilised where available and practical, though there's significant undeveloped resource in Africa, and in the US in the Yellowstone Caldera, though official resource estimates exclude this due to its protected status as a National Park. (Pointed, the USGS utterly omits the Yellowstone Caldera in its geothermal resource survey of a decade or two back.) As baseload power, geothermal is attractive. Capital-intensive "enhanced" geothermal has proved disappointing to date (see Australia's Habanero project).

Tidal energy is worth mentioning only because it's independent of the usual solar/nuclear axis: tidal energy actually represents a tap on gravitational potential of the Earth-Moon-Sun system. It's slightly more viable than wave energy, but save for a few very limited local applications, not practicable. Tapping the entire tidal potential of, say, the San Francisco Bay would not even power the city of San Francisco at current electric utilisation, let alone full energy demands, or of the greater Bay Area. And this would require entirely damming the Bay.

Nuclear fission suffers from a fuel shortage problem: known nuclear reserves would power present human energy needs for about 15 years, total. At present rates of utilisation, that lifetime is extended, but still comes in at under a century. There's the standard bickering about definitions of reserves, and talk of seawater extraction (of uranium, other fuels not being salt-water soluable), breeding (of plutonium), or use of thorium, under either existing or novel reactor designs. All three options have significant limitations, though some may be technologically feasible. The resulting energy system and economy would be fragile and risk-prone.

Fusion is as it's always been, the power source of the future. And always will be, as the punch line goes.

That's the lineup. Murphy has a good overview of numbers. Vaclav Smil in numerous of his books (Energy and Civilization and Energy in World History, an earlier edition of the same book, though with somewhat different organisation, as well as others) takes a deeper dive into many of these issues.

Mind that solving the energy problem is only one of numerous stumbling blocks between now an a long-term viable technological human civilisation. Numerous others exist, and the fundamental fact remains that economic growth (and its concommittant and requisite resource and energy growth) simply cannot continue indefinitely.