Rick Rys, Senior Consultant, ARC Advisory Group.

What are the primary drivers of the global shift toward green energy alternatives?

The shift towards green energy today is mostly a shift away from fuels that cause global warming and other pollution issues and a shift to meet growing energy needs. Biomass was the primary energy source for most of human history and it is still about 13-14 percent of global energy production, but evolving with more modern agriculture, farming, forestry, and biofuels. Even before the industrial revolution humans harnessed solar, wind and waterpower for tasks like farming, milling grain, and sailing ships. The industrial revolution was powered by coal, oil, and later natural gas as the dominant energy source. In the mid-20th century, nuclear power emerged as a new energy source, offering a carbon-free alternative to fossil fuels, but since the accidents at Chernobyl and Fukushima, new nuclear power has largely paused. More than 50 companies are designing new fission reactors. These reactors may result in an eventual renaissance, but they will not play a major role in the next 5 or 10 years, as it takes years for new reactors to be proven safe and cost competitive.

With innovations, manufacturing scale, and deployment experience, solar, wind, and battery power (SWB) have seen remarkable decline in cost and rapid deployment. This has not been the case for nuclear, coal, or gas. The cost of solar, wind, and batteries has plummeted over the past 20 years, making them increasingly competitive with fossil fuels. The cost of solar PV modules has fallen by about 90 percent in the last two decades from around $10.28 per watt in 2004 to around $0.25 to $0.50 per watt in 2024. Wind energy has fallen by approximately 70 percent over the past 20 years. Battery costs, particularly for lithium-ion batteries used in EVs and energy storage, have seen a decline of over 90 percent in the past two decades. Hydro and geothermal energy cost has been relatively flat.

While renewable costs have declined, coal power has become more expensive in the US due to stricter environmental regulations, competition from cheaper natural gas, and declining coal production. Globally, coal remains a significant energy source in many countries, particularly in Asia, but the rate of new coal power plants has declined sharply in China and other countries in 2024 and with renewable power on the grid, the high operating cost of existing coal plants means they are run at lower capacity factors and risk becoming stranded assets that are too expensive to keep running. The cost of natural gas-fired power has generally decreased in the US due to the shale gas boom, which increased supply and lowered prices. Low-cost gas was the main factor driving coal plants out of business, but now the low cost of SWB is driving gas out of business. Adding CCUS to remove CO2 adds about 30 percent capital costs and such plants use about 20 percent more gas than conventional gas power plants, so current CCUS gas power projects must compete with SWB. Globally, gas prices have been volatile, and costs vary by region. The cost of nuclear power has generally increased over the past 20 years. This is due to factors like high capital costs for new plants, safety concerns, and waste disposal challenges. Some countries with existing nuclear fleets and supportive policies (like France) have managed to keep nuclear power relatively cost-competitive. 

What are the emerging technologies that have the most potential to accelerate the transition to renewable energy sources?

There is unprecedented research into new green energy technologies and nuclear power. While there are promising advances for all of these, what is even more important is how technological advances are brought to market with engineering advances. It was engineering failures that pushed up the cost of the Vogtle nuclear plant. There have been multiple incremental advances in solar panel manufacturing, battery manufacturing, and wind turbine design and fabrication that has driven down the cost of green energy.

Some examples of upcoming potential innovations are perovskites for solar PV that could increase efficiencies from 20-22 percent to over 30 percent. New battery technologies such as sodium ion batteries can eliminate the need for lithium, nickel, or cobalt, reducing costs. New thermal batteries promise the storage of electrical energy for longer durations than batteries. New electric motors can have high efficiency but do not require rare earth metals. New digital tools for modeling and simulation, digital twins, automation, and AI are improving the way we design, deploy, engineer, manufacture, and operate new innovations. 

What innovations in grid infrastructure are needed to support widespread adoption of renewable energy?

We have all the essential grid technology today to support renewable power. Existing grids often lack the infrastructure to move renewable energy from rural sources to population centres. Offshore wind typically needs HVDC to move power to shore. Moving hydro and large solar can use HVDC too. 

It is hard to gain rights-of-way for new transmission lines so reconductoring is proceeding in many locations. New conductors may be heavier, requiring new towers. At the distribution level we see new innovative microgrids and behind the meter solar power growing faster than conventional grids. This new power generation needs to play well together with utilities. New renewables need more capable power conversion systems (PCS) systems that can provide grid services like VAR or voltage control, frequency regulation, and secure communications.

Increasing amounts of renewable power need a new type of grid-interactive customer that uses power when it is low cost and reduces power during peak loads or is expensive. This is a completely new business model for utilities and their customers, and it will need automation to adjust loads continuously as the price of power varies minute by minute. Exposing customers to a rate structure that changes the cost of power constantly needs new innovations in automating our power consuming devices. The real-time price of power, also called local marginal price routinely increases by a factor of 10 for minor weather events, and during major outage events it can increase by a factor of 1000 or more. Devices like EV chargers, electric hot water heaters, HVAC systems or any circuit breaker in your breaker box could be automated. Automation requires communication standards that don’t exist today. Smart meters and software running in your power consuming devices and monitored by your smart phone are coming soon. The FERC 2024 Assessment of demand response and advanced metering reviews the significant potential for demand response as a quantifiable, reliable resource for regional planning purposes.

What are the most significant challenges in scaling green energy technologies globally?

It takes policy and a sustained effort by governments to shape the energy landscape. Green energy must compete with nuclear and fossil fuels. Policy can use the carrot or the stick approach. Every energy industry receives direct and indirect subsidies, and this is a complex and highly debated topic. 80 percent of the cars sold in Norway last year were electric. This happened by consistent tax and other incentives and gradually increasing penalties on ICE vehicles. China installed more than 9 times as much renewal power in 2023 as the US because of their long-term goals and consistent policy. Energy consumers react to price signals that vary greatly by country.

Green hydrogen is now seen as one of the viable alternatives, but how feasible is this in the real world?

Hydrogen is essential to decarbonise refineries, ammonia, steel, and cement, but the shift to green hydrogen has been very slow. The main reason for this is the chemistry and thermodynamics of making hydrogen requires huge energy inputs. Green hydrogen at $12-$15/kg is much more expensive than grey hydrogen at 2-3$/kg. The steam methane reforming (SMR) process of making grey hydrogen is endothermic and requires heating a mixture of steam and methane. Making green hydrogen by electrolysis also requires massive amounts of electric power even if the cell technology were 100 percent efficient. While some hydrogen has been found in deep wells, such natural hydrogen is rare and thus hydrogen is used as an energy storing molecule much like batteries. Refining and ammonia production dominate the market but will only switch to green hydrogen when pricing favours green hydrogen.

How do you address concerns about the environmental impacts of manufacturing renewable energy components, like solar panels and wind turbines?

The ‘energy payback time’ (EPBT) of solar panels varies depending on the type and where they are installed. Monocrystalline Silicon is the most dominant type and has an EPBT of 2-3 years. Polycrystalline Silicon has an EPBT of 1.5-2.5 years and Thin-Film (e.g., CdTe, CIGS) can have EPBT under 1.5. Wind turbines have an average EPBT of 6 months to 1 year.

Recycling solar and wind components at the end of their life is increasingly feasible and becoming more important as these industries grow. Recycling solar panels can recover glass, aluminum, silicon, silver, copper, and other metals. Recycling wind turbines recovers steel, copper aluminum, and concrete as aggregate. Recycling wind turbine blades is the biggest challenge. In most situations the wind site foundation can be repowered with improved wind turbines.

Hands down, the best option for the green energy transition is the NegaWatt. This is the energy never used because it was never needed due to efficiency improvements or simple conservation. There are many ways to reduce energy consumption in industrial, commercial, and residential sectors. Energy audits, modeling and simulation, digital twins, AI, can improve design and operation. 

(The views expressed in interviews are personal, not necessarily of the organisations represented)

Rick Rys, Director of Consulting at ARC Advisory Group, Boston, is an expert process control engineer, familiar with instruments, valves, analyzers, control algorithms, safety systems, software development, and project management. Rick has worked in chemical, oil, gas, power generation (including fossil & nuclear), power T&D, renewable energy, pharmaceutical, paper and building automation areas. At ARC he performs research into and consults with clients on technology areas such as energy management, advanced process control (APC), simulation, and optimisation.