The 2016 Reines Lecture at UCI by Former Secretary of Energy Steven Chu
This is sort of a slide by slide outline of Physics Nobel Laureate Steven Chu’s Lecture at UC Irvine. Not only was the very large Barclay auditorium packed, but many were turned away on the web by the full reservation system. Steven Chu, Professor of Physics and Molecular and Cellular Physiology at Stanford University, gave a very intelligent talk, and presented his topics clearly to the general audience.
The talk was titled “Energy, Climate Change, and the Transition to a Sustainable World”. The talk will appear shortly on the School of Physical Sciences website.
The talk started with “Risks of Climate Change”. The global temperature has been looked at by skeptics as having plateaued since 1998 (when there was an anomalous one year jump). Chu pointed out that the excess heat has been found in the upper 2 km of the ocean. This has been done by the Argo floats that go down to 2 km. In April 2015, there were 3847 such probes.
More evidence is that the glaciers are melting. He showed a picture of the Muir glacier having disappeared. (As an aside, John Muir went to Alaska, staying with the Native Americans, in order to show that U shaped valleys like Yosemite were carved out by glaciers.). The GRACE satellite can measure the distance between its two satellites to within 1/10 of a human hair. This can determine the mass of areas of the earth below the satellite as it passes over them. (Prof. Famiglietti of UCI has been a spokesperson for this satellite.) Also, the ICESat uses laser ranging to measure ice, cloud and land elevations. These have determined that Greenland glaciers and West Antarctica are lowering.
During the last interglacial period, which was only 1 to 2 degrees C warmer than today, the sea level was more than 6.5 meters above sea level today. It could have been from 5 to 10 meters higher. While we are familiar with the IPCC estimate of sea level rise of 0.5 meters by 2100, the sea level hasn’t yet reached its equilibrium with the new radiation level increase. If the temperature rise eventually reaches 6 degrees C, all of Antartica and Greenland will melt, flooding the ocean to gain more than 70 meters in height.
Prof. Chu showed the graph of the CO2 concentration found in ice cores up to 800,000 years ago. In just the last few decades, it has risen sharply.
Then he went to the question “Is it due to human activity”. He explained Carbon 14 dating , with radioactive Carbon 14 cycling through life forms. But once a life form dies, the Carbon 14 stays in the life form, and radioactively decays with a 5700 year half-life. When is turned into a fossil fuel over millions of years, there is no Carbon 14 left. So when it is burnt, the increase in CO2 has only the normal Carbon 12, not 14. This agrees with calculations of the amount of Carbon burned. About half of new Carbon goes into the ocean, and has made the ocean 30% more acidic with Carbonic acid.
He compared this to the risk of lung cancer, which in 25 years makes the odds 25 times higher for smokers. But if someone chooses to smoke, the cancer is limited to the smoker himself, and does not harm his offspring (assuming no second hand smoke). But in the case of fossil fuel burning, the risk of consequences is born by and suffered through by future generations.
The costs of climate change are climate refugees created by the collapse of agriculture, or rising sea levels.
If we keep the same rate of fossil fuel burning for the next 20 years, we will have created enough CO2 to raise the temperature by 2 degrees C above the pre-industrial level. (We have already raised the temperature about 0.7 degrees C above the pre-industrial level.)
Fossil fuels will continue to increase. In the last few years the daily US oil production has increased by 4.5 million barrels from fracking. In the future there will be untapped tight oil, heavy oil, off-shore oil, and other sources.
Chu said that we have to transition to better solutions. If we don’t find them, the oil and gas will come out of the ground. One example is California and then US efficiency laws on home appliances such as fridges and air conditioning (pioneered by UC Berkeley Rad. Lab). This has not only brought down the use of electricity running these appliances, but brought down the cost of the appliances themselves!
We now get to the third part of the talk which is the future sources of energy. On the US wind map, the high wind is offshore, in the Midwest, and on the Great Lakes. The cost of wind has been reduced to less than 2.5 cents per kiloWatt-hour (kWh). Natural gas, which has dropped due to fracking, goes at 5 cents/kWh. New 140 meter high wind turbines have a 45% duty factor (as opposed to the usual 33% of old small turbines). The new standard is going to 7.5 megaWatt (MW) in offshore wind. This is 2.5 times greater than recent 3 MW turbines.
Solar Power has dramatically lowered in cost, from 60 cents/kWh to less than 5 cents/kWh. Solar power in the US is now greater than 10,000 kW. The US government actually made $5 billion on solar loans. The solar industry does not need government loans any more since it can get bank loans.
By 2020, solar will be down to 3 cents/kWh, and by 2035-40 renewable energy will be down to 2 cents/kWh. In the US, wind is now at 5% of our power, and solar is greater than 10%. Because of the fluctuations in renewable energy, we need backup power and an enhanced transmission grid. Utilities work on the principle that energy-on-demand must be available. Utilities should partner with solar installers since they can sell solar power at 9 cents/kWh and use the rest for installation and the power grid. Within a year there will be cheap 12 kWh batteries available for households, to give them immunity from blackouts.
China’s plan for 2020 is to have ultra-high voltage lines. They are spending $350 billion on this across the country, giving a capacity greater than 200 GigaWatts. This grid uses 11 megaVolt direct current lines that lose less than 5% of the power transmitted.
In the near future, we can boost wind and solar to 50% of our power. The rest should be one quarter fossil fuel, (to fill in for the renewable fluctuations), and one quarter nuclear power.
Nuclear power is safe. 4,000 times as many people die from coal per unit of power than die from unit of nuclear power. 900 times as many die from oil related power as nuclear power per unit of power.
With renewable power, energy storage can be accomplished by pumping water to higher reservoirs.
The Tesla battery cost $30,000. That works out to $360 per kWh of storage. He is working on a lithium-sulfur battery that could increase energy density five fold, increase the charging rate ten fold, and at 1/3 the cost.
For the summer versus winter storage problem (sunshine is less powerful in the winter), we can use renewable energy to separate water into hydrogen and oxygen. They can then absorb carbon capture CO2 to make liquid hydrocarbon fuel. The hydrogen has to be produced at $1.50 per kg. Today it costs $5 per kg.
He mentioned funding by ARPA-E, EV of electric vehicles, and SunShot.
Prof. Chu ended his very informative talk with the Native American saying: “We do not inherit the land from our ancestors, we borrow it from our children.”
