What Fusion Energy Can Learn from Solar Energy Adoption
One question that we always get at The Fusion Report is “when will fusion energy be here, and how fast will fusion energy be adopted?” This is really the trillion-dollar question that fusion energy is facing. To help answer questions like this, it is often interesting to look at other similar transitions and see if there are any lessons that can be learned from them.
The most recent transition in the energy generation sector has been the rise of photovoltaic (PV) solar energy. To set the context for this, in 2024 7.35% of US electricity was generated by solar energy. Worldwide the number is slightly lower, with 6.9% of the world’s electricity generated by solar energy in 2024. China generates the highest absolute amount of solar electricity, with 609,921 megawatts (MW) of generation capacity and 664,439 gigawatt-hours (TWh) estimated to be generated in 2024. More interestingly, US solar electricity generation grew to 10.64% of total electricity generated in April 2025, surpassing 10% for the first time in the US. Worldwide, solar electricity is forecasted to reach over 25% of total worldwide electricity generation by 2050, according to the most recent study by the International Energy Agency (IEA). This will be a mix of PV solar electricity (16%) and concentrating solar power plants (CSP; 11%), which uses an array of mirrors to focus solar energy on a heat collector that then drives turbines and generators.
What Enabled Solar Electricity’s Growth Over The Past 20 Years?
The most amazing thing about solar energy is how fast it has been adopted. Since the advent of the first solar energy installations in 1954, it took solar energy to reach 1 terawatt (TW) of installed electrical generating capacity worldwide in 2022. The second terawatt of electrical generating capacity took two (2) years – we reached 2TW of capacity last year (2024). And this rate is not expected to ease up anytime soon – solar generation capacity is expected to reach between 5.4TW and 7.1TW worldwide by 2030, according to the IEA.
What were some of the factors enabling solar electricity to grow at this rate? Solar’s recent rapid growth was driven by a classic "learning curve" effect, where increased deployment led to technological refinement, which itself led to continually reduced costs for solar panels. Additionally, early solar photovoltaic (PV) panels were inefficient, and were primarily adopted by early-stage innovators and affluent, environmentally conscious homeowners. Over the past twenty-five years, both state and federal policies have played a crucial role in pushing this market forward, especially in states with high electricity costs and plentiful sunshine such as California. These policies have included tax credits, subsidies, and feed-in tariffs to help reduce the initial cost of purchasing solar panels, creating the market demand needed to scale up manufacturing. Finally, the “modular” nature of solar electricity generation (i.e., panels) enabled its deployment at various scales, from a single rooftop to vast solar farms.
How Does Fusion Energy Differ From Solar Energy?
As I am sure a number of you out there will say, “we still don’t have working fusion energy machines”, or “fusion and solar are fundamentally different”. This is absolutely true in many respects:
- Distributed vs Centralized: Solar is a distributed energy production resource, while fusion (like natural gas, coal, and nuclear fission) is more of a “centralized” power source. However, more modular versions of natural gas plants (also known as micro-cogeneration units) are numerous, and small-medium (nuclear fission) reactors (also known as SMRs) are being developed today as distributed energy resources.
- Public Perception: One of things that has helped solar power is it’s generally positive public perception, as opposed to large power plants which have a negative perception. However, public attitudes change over time. Large grid-scale solar installations, especially those with battery-electric storage systems (BESS) are now seeing a large amount of public opposition (mainly due to the negative potential of lithium-ion battery fires), while public support of the Commonwealth Fusion Systems (CFS) sites in Massachusetts and Virginia seem high, as fusion has done a good job differentiating itself from nuclear fission.
One concept that fusion energy can learn from solar energy’s success is the idea of “factory-built”, and its corollary of interoperable components. Solar energy panels, and the inverters that support them, are all factory-built, enabling rapidly decreasing costs and high levels of quality. While the differences between fusion and solar make the same level of modularity difficult, concepts like CFS’s high-temperature superconductor (HTS) magnet factory are a step in the right direction towards this sort of modularity. Similarly, replaceable parts like first walls, modular thermal blankets, vacuum pumps, fuel injection systems, lasers/pulsers, and similar systems will help reduce costs and over time by enabling automated construction. Finally, using a ‘cookie-cutter’ approach to fusion machine designs also is a right step towards cost reduction.
Conclusion: Different Timeframes, but Lessons to be Learned
While fusion might not “explode” in the same way or in the same timeframe that solar electric growth has, its growth still has lessons to impart to the fusion industry. By stressing the use of modular, interoperable components and repeatable designs where possible, it is highly likely that fusion energy can also grow rapidly, enabling rapid adoption of fusion energy as one of our next important sources of electricity for the globe. Which is good, because we all are going to need more electricity!
