GE and Southern California Edison recently worked on a project together to more efficiently ramp up generation in the evening when the sun is starting to set and people are coming home to turn everything on. My research assistant a.k.a. my mom just pointed me to this interesting new method that combines a lithium ion battery system with two existing natural gas turbines. The total output of the system will be 50 MWs, and they are calling it the LM6000.
Before there was so much solar and wind power on the grid, energy supply and demand were smoothly coordinated by slowly ramping up natural gas turbines for up to twelve hours. This process worked fine in the old days, but with today’s variable renewable energy sources it is a much bigger challenge. The traditional system of ramping up a gas turbine wasted a huge amount of fuel and therefore released a ton of carbon into the atmosphere. The reason for this is that traditional systems have to burn fuel for hours while they are is standby mode and waiting to connect to the grid.
With the LM6000 system SCE will be able to instantly begin discharging power from the energy stored in batteries while they ramp up the gas turbines. This system allows for much more flexibility then current technology because they can literally start providing energy supply in seconds as opposed to hours. This is going to add stability and reliability to the grid for all of the end customers. By having this capability SCE is also positioning itself to be able to acquire more solar Power Purchase Agreements (PPA) without fear of how to balance supply and demand. Another benefit to the new set up is that is that it can be economical because instead of wasting all of that fuel to start up the gas turbines now they just turn on the battery. Then as the gas turbines start ramping up. All of that energy can actually be sent into the grid instead of being wasted as heat.
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Lead Photo Credit
If you have been following my blog I think you will know that a key challenge to bringing renewable energy to mass market is storage. We have the ability to generate a huge amount of cheap solar energy during the day time, but we really struggle to deliver it at night time. One approach to solving this lies in battery storage. Battery storage has a lot of potential (no pun intended), but we are not able to store municipality levels of energy in batteries yet. Another method that is being tested to store energy is using compressed air. The idea is that we can compress air with electricity generated by solar panels during the day, and release it across a turbine at night time.
This is a clever idea and it does actually work. The problem is that every time we convert energy we lose some efficiency. Air compressors have notoriously low efficiencies which can be between 65% and 80%. This means that for every 10 KW you put into compressing air, you only get about 7 KW of usable air. At this point a reader might ask, “I thought we can’t create of destroy energy, so where does the rest of the energy go?” Great question, I’m glad you asked. You are correct that we can’t destroy energy in reality most air compressors lose a lot energy in the form of heat. All of the energy that is lost in the process of compressing and expanding air across a turbine makes it hard to remain economical.
But all hope is not lost for this method of storing energy. An innovative company called LightSail Energy seems to have figured out a better way. LightSail Energy uses technology that both compresses air for later use, and captures and stores the waste heat for later use. By capturing and storing the heat, LightSail is able to greatly increase the efficiency of the process. Which means they are able to make this type of project much more economical. Another nice thing about compressed air energy storage is that you can scale it up by storing air in large underground caverns.
This company really understood the root problem and came up with a viable solution to solve it. Keep an eye out for LightSail Energy in the future because they are doing a lot of things right. They recently received large rounds of funding from big investors including Bill Gates.
If you have any thoughts on this innovative new technology please share them in the comments section.
Lead PC: https://www.waterpik.com/shower-head/buying-guide/images/high-pressure-shower-head-buying-guide.jpg
CAES PC: https://www.pge.com/pge_global/local/images/data/en-us/about-pge/environment/what-we-are-doing/compressed-air-energy-storage/caes.jpg
It seems like the auto industry is heading towards a future of more electric and less gasoline. This is great for the quality of our air and our children’s air. It is also great for reducing the amount of carbon dioxide that we are putting in the atmosphere (assuming they get their electricity from renewable sources). But the coolest part about all of these electric cars taking over our driveways and garages is that they each have a battery built in to them. In a previous blog post I talked about one of the biggest barriers of solar and wind energy is that they fluctuate and we need storage to offset those fluctuations. Soon all of these electric cars will be plugged into the grid and they will communicate with it in order to give and take power as necessary.
Of course a majority of the time, cars will be taking power off the grid so that they can have fully charged batteries for the drive ahead. But it is also likely that when the sun goes down, a small fraction of the electricity stored in millions of cars will be used to pump up the electricity of the gird to supply the night time demand. If we make batteries that can serve multiple purposes such as powering our vehicles and balancing the grid, they become more cost effective and there is more incentive for people to buy them. Just investing in batteries to balance the grid and nothing else is a much tougher sell.
When cars become one with the grid, they will also be able stabilize sudden power failures or sudden spikes in power. Currently if some generating equipment goes offline, it can mean a power outage for customers in the affected area. With car batteries supplementing the grid, these bursts and shortfalls will all be smoothed out. There will be less power failures, and less need to rely on ramping natural gas turbines up and down.
Do your part, go out and buy a plug in electric vehicle today!
Lead PC: https://scrapit.ca/wp-content/uploads/2014/04/Large-Car-Cropped.jpg
Sun PC: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2015/25-researcherss.jpg
Today at work I attended a training about how to handle settlements in the energy imbalance market (EIM). It was a long training, but that is not the point. The point is that this is a new market place that has developed in recent years for industrial suppliers of power to be able to ramp up and ramp down their generation as the grid demands. One of the main reasons that this market has developed is because of the large addition of variable renewable energy (VRE). VRE is energy like solar and wind that has large swings in its output.
In my post ‘The Energy Storage Challenge’ I talked about how we need to develop more storage technologies and increase their presence in the market. That is still very true but until we get to that point the energy community has come up with this solution to get us through the transition. The idea is that we can look at the bigger picture of all of the electricity available on the grid. Then when the sun goes down or some clouds cover a certain area, this EIM can dispatch more power from another generator that is also on the grid.
This is a pretty good temporary solution, and it allows the grid to remain stable but it means we are still heavily reliant on non-renewable energy sources. Basically for every megawatt of wind or solar energy that is produced, we still have to have 1 MW of coal or natural gas to offset it. So we are still dependent on these other technologies. This dependence will continue until we are able to transition into mode where we can generate extra solar energy in the day and store it so that we can use it at night time.
I think this blog post went a little into the weeds but if you have any thoughts on the EIM please leave a comment below.
Lead Photo Credit: http://lighttalk.via-verlag.com/wp-content/uploads/2015/09/solarcoal-620×330.jpg
Story Photo Credit: http://static4.businessinsider.com/image/529e0871eab8ea8f3b69ae5e/green-energy-could-crash-the-us-power-grid.jpg