Key Lessons from the 2009 American Recovery and Reinvestment Act:
The Recovery Act’s investments in clean energy research and deployment were largely successful, particularly in promoting renewable energy and energy efficiency. The creation of new institutions like ARPA-E and revitalizing existing programs like SunShot brought in talented individuals who made a significant impact. The loan program, despite criticism, played a crucial role in supporting companies like Tesla and initiating large-scale solar and wind farms. The success of the loan program in demonstrating the feasibility and profitability of large-scale renewable energy projects transformed Wall Street’s perception of these investments.

Success Stories:
Tesla, with the help of a DOE loan, built its first plant and repaid the loan ahead of schedule. 15 million smart meters were installed in homes and buildings. 650,000 low-income homes were weatherized. The first utility-scale solar farms over 100 megawatts were financially engineered by the Department of Energy.

Challenges and Criticisms:
The loan program faced criticism for taking on too much risk, particularly in supporting companies like Solyndra, which eventually went bankrupt. The Recovery Act’s focus on short-term economic stimulus may have come at the expense of long-term energy innovation.

Implications for Today’s Economic Crisis:
The Recovery Act’s lessons offer valuable insights for addressing the current economic crisis and promoting a green recovery. Investing in research and deployment of clean energy technologies can create jobs, stimulate economic growth, and address climate change. The private sector and government should collaborate to create a favorable investment climate for clean energy projects.

What Went Well:
The Clean Energy Ministerial, the U.S.-China Clean Energy Research Program, and the U.S.-India Research Program were successful in fostering international collaboration on clean energy. The Energy Innovation Hubs program stimulated research and development in clean energy technologies. The Recovery Act provided funding for weatherization programs, which helped low-income families reduce their energy bills. The distribution of synchro phasers, which measure voltage and phase, helped to improve the stability of the electric grid.

What Could Have Been Done Better:
The weatherization program should have included a controlled experiment to accurately assess its effectiveness. The government should have required recipients of funding to share data and allow for analysis to ensure the effectiveness of the programs. The government should have done more to encourage the sharing of data from synchro phasers to enable a full view of the electric grid. The government should have considered the long-term sustainability of the programs when making funding decisions.

International Collaboration Priorities:
Steven Chu emphasizes the importance of the Clean Energy Ministerial as a platform for international collaboration. The focus is on sharing best practices and policies to promote energy efficiency and reduce energy costs in developing countries. Chu stresses the need for honest discussions and the sharing of successful strategies.

Energy Storage Challenges:
Pumped hydro storage is the dominant form of energy storage in the U.S., but its capacity is limited. The need for long-duration energy storage (10-100 hours) becomes significant when aiming for high renewable energy penetration (80%). Developing cost-effective energy storage technologies is crucial, especially those that can compete with lithium-ion batteries.

Weatherization Programs:
Retrospective studies of weatherization programs show mixed results. One study found that the Recovery Act weatherization program did not recoup its investment due to rapid expansion and implementation issues. Another study by Michael Greenstone suggests that weatherization programs may not be cost-effective, with high costs per ton of carbon emission saved.

Appliance Standards and Data:
Chu highlights the success of appliance standards in reducing energy costs and improving energy efficiency. Data analysis shows that the purchase price of efficient appliances often decreases over time due to learning curves and technological advancements. Resistance from economists who rely on mathematical models and disregard empirical data is noted.

Long-Duration Energy Storage Research:
A call for proposals focused on developing long-duration energy storage technologies that are more affordable than lithium-ion batteries. The goal is to achieve costs in the range of $100 per kilowatt and $20 per kilowatt-hour for 50-hour storage. Alternative energy storage methods, such as hydrogen production through water electrolysis, are also being explored.

Hydrogen Production Costs:
Current hydrogen production costs are around $1 to $1.50 per kilogram, with significant transportation costs. At current electricity prices of $40 per megawatt-hour, the cost of producing hydrogen through electrolysis exceeds its market price.

Impact of Electricity Costs:
Lower electricity costs, such as $1.50 per kilowatt-hour, would make electrolysis more economically viable. With efficient electrolyzers, hydrogen production costs could be reduced to a competitive level.

Future Cost Projections:
Estimates from various sources indicate that hydrogen production costs are expected to decrease over time. This is driven by anticipated lower costs and increased availability of excess renewable energy.

Electrolysis Technology:
Electrolysis of water is a well-established technology, but it is being re-examined for hydrogen production. Oxygen and hydrogen bubbles form during electrolysis due to the presence of catalysts. Bubble formation can increase electrical resistance and block catalytic sites, affecting efficiency.

Minimizing Bubble Formation:
Researchers are exploring methods to avoid bubble formation during electrolysis. This involves allowing gases to escape quickly through hydrophilic borders, reducing resistance and improving efficiency.

Ongoing Technical Developments:
Efforts are underway to improve electrolyzer technology and address technical challenges. These developments aim to enhance the efficiency and cost-effectiveness of hydrogen production through electrolysis.

Hydrogen Production and Storage:
Hydrogen produced from steam methane reforming (SMR) has a high carbon footprint due to CO2 emissions. Electrolytic formation of hydrogen can reduce CO2 emissions and potentially make hydrogen a negative carbon fuel if biomass is used efficiently. Hydrogen is being considered for stationary storage, but not for general vehicle fueling due to lack of distribution infrastructure. Repurposing natural gas lines for hydrogen storage is challenging due to hydrogen embrittlement of steel pipes. Fiber-reinforced polymer pipes may be a viable alternative, but their cost and effectiveness need further research.

Long Duration Energy Storage:
A recent RPE call for proposals sought energy storage technologies that can store electricity for several days. The goal is to keep the cost of electricity storage below 5 cents per kilowatt hour, comparable to natural gas standby generation. The most efficient energy storage method is pumped hydro storage, which involves pumping water up a hill and releasing it through a generator to generate electricity. Pumped hydro storage has high round-trip efficiencies (up to 85%) but faces challenges in permitting and environmental concerns.

Global Hydroelectricity and Pump Storage:
China leads the world in hydroelectricity, and they aim to increase their capacity by 50%. Japan is the global leader in pump storage, demonstrating the potential for large-scale energy storage using this technology.

Pumped Hydro Storage:
China will soon lead in pump storage technology, with the US catching up in recent years. Pump storage utilizes gravity to store energy by pumping water uphill when electricity is abundant. When energy is needed, the water is released downhill through turbines to generate electricity. The water is recirculated between an upper and lower reservoir, minimizing waste.

Details of Pumped Hydro Storage Systems:
Turbines can operate in both directions, allowing for energy storage and generation. Variable speed generators optimize efficiency at different speeds. The scale of pump storage systems is immense, with large generators and pipes. Efforts are underway to standardize parts and reduce costs.

Global Potential for Pumped Hydro Storage:
A website identifies potential pump storage locations worldwide, indicated by red dots. Suitable locations have large height differences, typically 100 meters or more. Pump storage is a promising technology for energy storage and grid stability.

Economic Viability of Pump Storage:
Abandoned mines offer potential sites for pump storage due to pre-existing hollow spaces, reducing excavation costs. Environmental concerns, such as water usage, can lead to additional expenses like desalination plants. Pump storage projects have long timescales, with generators lasting 50 years and dams lasting 100 years.

Challenges in Economic Evaluation:
Discount rates, typically ranging from 7% to 10% per year, diminish the value of long-lasting energy assets like pump storage. This economic hurdle hinders pump storage’s competitiveness compared to other energy storage options.

Resurgence of Interest in Pump Storage:
Pump storage is experiencing renewed attention due to its proven effectiveness and longevity. Pump storage is now considered more economically viable than chemical batteries in certain locations.

Innovative Pump Storage Concept:
A theoretical physicist at UC Santa Barbara, Phil Lubin, has proposed an innovative pump storage concept. Details about this concept are not provided in the given text.

Idea of Pump Storage:
Utilizes the depth of the oceans to store compressed air in canisters placed on the seafloor. The displacement of seawater creates a potential energy source. Thin pipes withstand high pressure and transfer compressed air.

Isothermal Cooling and Heating:
Heat exchange mechanisms manage temperature changes during compression and expansion of air. Isothermal cooling prevents excessive heating during compression, reducing energy loss. Isothermal heating recovers heat during expansion, maintaining pressure and energy efficiency.

Adiabatic Storage:
Adiabatic storage aims to minimize heat loss during compression and expansion. Heat storage and recovery systems are crucial for efficient energy transfer. Adiabatic storage technology is still under development and faces challenges in maintaining energy storage temperature qualities.

Storing Energy in Salt Domes:
Salt domes can be excavated and used for energy storage, particularly for pump air storage, hydrogen storage, and natural gas reservoirs. The process involves pumping in water to create brine, hollowing out the dome, and sealing it with a caprock.

Isothermal Storage:
Isothermal storage aims to minimize heat generation during compression and expansion of gases. By maintaining constant temperature, the process resembles a mechanical motor, eliminating the need for additional heat. Achieving efficient isothermal compression and reheating can make large-scale energy storage devices more viable.

Lifting Weights vs. Pumping Fluids:
Lifting weights and sealed cables are less efficient than pumping fluids, especially water. Water’s incompressibility prevents energy loss, making it a preferred medium for energy storage.

Electricity to Heat Conversion:
Using electricity to generate heat can be cost-effective in regions with low natural gas prices and carbon taxes. Electricity-based thermal storage becomes competitive with natural gas when considering the cost of carbon emissions.

Novel Ways of Heat Conversion:
Instead of using resistors in molten salt, more efficient methods of converting electricity into heat are being explored. The focus is on innovative technologies that minimize energy losses and improve performance.

Carnot Batteries:
Carnot batteries use electricity to charge hot and cold reservoirs, which are then used to generate electricity through a heat pump and turbine. These systems are being actively researched and developed.

Bob Law’s Four-Reservoir Cycle:
Bob Law proposed a modified Brayton cycle heat pump with four reservoirs instead of two. This design operates at lower temperatures, reducing concerns about high-temperature materials. The cycle involves transferring energy between hot and cold reservoirs during charging and discharging phases.

Key Concepts and Innovations:
Dr. Chu introduces the concept of regenerators in Thermal Energy Storage (TES) systems, which allow for more efficient energy transfer between cold and hot states, mimicking pump storage. The potential efficiency of this system is explored, with claims of reaching up to 70% Carnot efficiency under ideal conditions. Supercritical carbon dioxide is gaining attention as a fluid for these turbines due to its advantages, including a density half that of water, leading to compact turbine sizes.

Flow Batteries and Long-Duration Storage:
New flow batteries are being developed, with the potential to achieve 100 days of energy storage. Combining these batteries with untapped pump storage and thermal storage could enable 80% renewable energy use.

Hydrogen’s Role in Long-Duration Storage:
Dr. Chu discusses the necessary investments in research and infrastructure to make hydrogen a viable long-duration storage technology. Private sector involvement, such as Shell’s investment in electrolysis and hydrogen-related technologies, is highlighted. Hydrogen’s potential applications include stationary storage, centralized fueling, and transportation, particularly for long-haul scenarios. Hydrogen’s role in converting CO2 into hydrocarbons is also being explored.

Government and Industry Involvement:
The US government invests in hydrogen research through the Department of Energy (DOE), while American oil companies are yet to make significant contributions in this area. Shell, a major energy company, is actively investing in hydrogen technologies, particularly electrolysis and pipeline infrastructure.

Department of Energy Restructuring:
Steven Chu emphasizes the need to attract talented individuals to the Department of Energy (DOE) and reduce bureaucratic hurdles. Excessive paperwork and compliance requirements discourage companies from seeking government loans, hindering the DOE’s ability to fund promising technologies. A more efficient approach involves utilizing the private sector to distribute funds, as seen in the COVID-19 crisis where banks were entrusted with dispersing aid. The DOE should collaborate with banks to streamline the loan application process for weatherization housing and other energy efficiency programs. Continuous vigilance is required to combat bureaucratic growth within the DOE, which can hinder its effectiveness.

Global Supply Chain for Batteries:
Chu stresses the importance of developing a domestic supply chain for critical technologies, including batteries, to prevent dependence on other countries. China’s dominance in rare earth minerals and integrated circuit chips poses a strategic challenge, highlighting the need for government support to protect key industries. Subsidies, similar to those provided to Airbus and Boeing, may be necessary to ensure the competitiveness of American industries against foreign competitors.

Optimal Energy System Design:
Demand-side management, thermal inertia in buildings, and decoupling cooling from air circulation can significantly reduce the need for energy storage. However, energy storage remains essential for a resilient grid, and the amount required depends on factors such as transmission and distribution infrastructure. Optimizing the system involves balancing the use of long-distance transmission, energy storage, and demand-side management. China’s advancements in high-voltage DC transmission technology provide a model for the United States to emulate.

Small Modular Pumped Hydro Systems:
Chu advocates for the development of small modular pumped hydro systems as a viable alternative to large dams. These systems can be built in factories and shipped worldwide, reducing environmental impact and regulatory hurdles. They offer a cost-effective and scalable solution for energy storage, comparable to batteries.

Distributed Microgrid Systems:
Distributed microgrid systems can enhance the resiliency of the energy grid by providing local generation and storage. The optimal approach involves a combination of centralized and distributed energy resources, considering factors such as transmission costs and site suitability.

Geothermal Energy:
Geothermal energy offers zero-carbon electricity and potential for continuous operation, eliminating the need for energy storage. However, the cost of geothermal energy remains a challenge, hindering its widespread adoption. Research and development efforts are needed to reduce the costs associated with geothermal exploration and drilling, and to expand its applicability beyond regions with high thermal gradients.

Natural vs. Enhanced Geothermal:
Most current geothermal energy sources are natural, relying on hot springs and high local thermal gradients. Enhanced geothermal involves pumping fluid (like carbon dioxide or water) into hot rock to extract heat.

Challenges of Enhanced Geothermal:
Enhanced geothermal is limited to areas with high thermal gradients, often geologically unstable regions. Pumping fluid can cause tremors, raising concerns about safety and public acceptance.

Fluid of Choice:
Carbon dioxide is a potential fluid for enhanced geothermal due to its lower density and ability to seep through rock with less resistance compared to water.

Drilling Technology:
Rapid small board drilling using laser technology is being explored to facilitate enhanced geothermal operations.

Sustainability of Enhanced Geothermal:
Unlike natural geothermal sources, enhanced geothermal is not a permanent source. Extracting heat over time reduces the thermal gradient, eventually depleting the heat resource.

Geographic Limitations:
Natural geothermal sources are geographically limited to areas with hot springs and high thermal gradients. Enhanced geothermal could potentially be used anywhere, but its feasibility and sustainability need further exploration.

Efficiency Potential:
Pumped thermal energy systems, if successful, can achieve high efficiency, around 65%.

Cleantech 2.0 and Lessons from Cleantech 1.0:
The discussion moves on to Cleantech 1.0 and Cleantech 2.0, but the transcript provided does not contain the answer to this question.

Investment Challenges in Clean Tech:
Investors in clean tech during the Obama administration faced difficulties due to unrealistic expectations and a lack of understanding of the energy industry’s unique characteristics. Energy companies have smaller margins, longer timescales, and require extensive engineering expertise, which differs significantly from internet and information tech companies.

Manufacturing Expertise in Energy:
Established companies like GE and Siemens have a long tradition of engineering excellence, which startups often lack. Tesla is an example of a company that had to relearn manufacturing processes that traditional automakers had already mastered. Mechanical and chemical engineers have a deeper understanding of thermodynamics than physicists, making their expertise crucial in energy industries.

Global Climate Change Mitigation:
The Paris Agreement’s success was partly due to the collaboration between the US, China, and the EU. The current strained relationship between the US and China is hindering progress on climate change mitigation. Addressing climate change requires listening to scientists, understanding the risks, and developing cost-effective strategies.

International Collaboration and Developed Countries’ Role:
The US, China, and the EU should lead the way in establishing a global carbon price and promoting sustainable practices. Developed countries have more wealth and can better adapt to climate change, and they should provide financial assistance to developing countries. Capital flow to developing countries is essential, as they have a small carbon footprint and can benefit from technology transfer.

US Role in Technology and Collaboration:
The United States has been a leader in energy technologies but needs to collaborate internationally again. Energy-efficient buildings and other sustainable technologies can be developed through collaboration between countries and industries.

Sharing Best Practices:
Countries like China and the US can share best practices in constructing energy-efficient buildings, promoting innovation and collaboration.

Carbon Pricing:
Carbon pricing is crucial in reducing carbon emissions. Europe’s experiment with a $30 per ton carbon price proved ineffective. A carbon price of $60 or higher, with confidence in its stability, is necessary to drive meaningful change.

Stimulating Innovation:
Carbon pricing and the demand for clean energy technologies will drive innovation. Improved battery technology and thermal storage are expected to emerge.

Battery Costs:
Battery costs are projected to decrease below $50 per kilowatt-hour, making them more affordable and accessible.

Global Energy Dialogue:
The next Global Energy Dialogue will feature Chad Holliday, the chairman of the board of Royal Dutch Shell, on July 7th. The dialogue series will continue every two weeks, providing a platform for discussions on energy-related issues.