This episode of real engineering is brought to you by brilliant a problem solving website that teaches you to think like an engineer
Money climate stabilization plans depend upon the power sector moving towards net zero carbon dioxide output by 2050
To achieve this fossil fuel power plants are beginning to close around the world coal
The world's stable energy source for centuries has steadily fallen out of favour since 2015
With a 70% drop in new construction projects this decline cannot be entirely pinned on shifting global
Attitudes to climate change economic pressures have been the driving force for many of the closures as solar and wind energy
continues to get cheaper
California is among the most proactive places in the world when it comes to renewable energy and they have a good reason to be
droughts and wildfires have plagued the state in recent years and
Trends indicate that they will continue to get worse with increasing global temperature over the past eight years
Californian energy sources have shifted dramatically in
2010 their energy sources looked like this with the majority of energy coming from natural gas
hydroelectricity nuclear and geothermal in
2018 each of these energy sources has dropped in the percentage of total energy production with solar rising to an astounding
19% in just eight years and wind more than doubling to 6.5 percent
last year Californian lawmakers set a goal of reaching
100% renewable energy for the states by 2045 and at this rate California are on track
But California's progress is about to get a lot more expensive and difficult a switching to 100% renewable energy
Even in sunny California is not quite as easy as installing solar panels
Let's discover. Why by visiting Moss Landing in beautiful Monterey Bay
This natural gas power plant began producing energy in 1950 with the nameplate power capacity of six hundred and thirteen megawatts
By 2002 it was the largest power plant in the state of California with the power capacity of two thousand five hundred and sixty
megawatts it has gone through many changes in those seventy years of
Operation with older less efficient systems been retired and replaced with modern more efficient and cleaner systems
Last year, the latest update for the facility was announced with an unprecedented battery storage facility totalling
567 megawatts of storage making it the largest battery installation in the world
this battery storage facility is designed to take over the Moss Landing power plants role as a
Peeker station providing surges of energy to the grid when needed and thus decreased California's use of natural gas
California's grid operator provides life and historical stats on power generation and consumption
Let's take a look at a typical day in the state. This is the energy supply for May 24th
2018 this line is the power gained from hydroelectricity
We can see a steady base load is provided by nuclear energy from the Diablo Canyon power plant
Which is this flat output line this supply deviates
very little throughout the year
Providing a steady two thousand two hundred and eighty megawatts about 90 percent of the needs of the state this power station rarely varies
Its load because it takes a tremendous amount of time to do so here
We can see the very noticeable spike of renewable energy starting at 6 a.m
As the Sun rises on this day thirty four point five percent of California's electricity was provided by renewable energy
51% of that being from solar this is fantastic
But we have one big problem solar energy began to drop off at 5 p.m
just as California's population was about to leave work and get stuck in traffic for hours before arriving home to turn on their
Air-conditioning cook their dinners and watch TV this results in a peak power demand at eight thirty
Four and a half hours after our solar supply peaked in order to deal with this demand
California begins to ramp up its natural gas power stations, which can quickly raise their energy output to deal with surges in demand
California also imported a significant amount of energy from other states primarily wind and hydro electricity from the Pacific Northwest a
Nuclear coal a natural gas from Nevada as California looks towards a carbon neutral energy supply
They're looking to remove these natural gas power state and replaced them with batteries that can store excess solar electricity
So it is available when needed?
This battery installation in Moss. Landing is going to fill that role and make no mistake
Batteries are now cheap enough to be a financially viable solution for California at small scales like this
Allowing power companies to buy cheap solar energy and sell it on for a profit when demand requires
However, this business model does not last very long as we scale up
Let's calculate how much battery storage California would need to replace. Just this natural gas peaking power on May 24th
2018 step 1 Don load the data from this day and graft the natural gas power output
This data has a resolution of five minutes
But we are going to reduce a resolution to an hour to make the data easier to Paris
We will assume our new grid will contain a steady base load of natural gas power at four thousand two hundred and twenty megawatts
which is a 10% drop in our natural gas use for the day and a
1.7 percent drop when expressed as a percentage of total energy use on the day in an ideal world
I think California would be generating this base load using nuclear energy
But that seems unlikely as early last year regulators voted to close the Diablo Canyon power plant
California's last nuclear power plant
We can now clearly see the energy we need to provide with batteries as this area that rises above our base load
To calculate it
We simply need to calculate the area of this section which will give us our battery storage requirements in megawatt hours
This comes out to be about eleven thousand two hundred megawatt hours of energy storage
Tesla's one hundred and twenty-nine megawatt hour battery storage facility for horns Dale firm in Australia came with a price tag of
fifty-six million dollars
Extrapolating that figure out to an eleven thousand two hundred megawatt hour battery
We could expect a total cost of four point eight six billion dollars
We would likely be able to achieve a lower battery cost over time as battery prices continue to lower over time
It's not an absurd number Diablo Canyon power plant, which has about five times the daily energy output cost
13.8 to construct. However, it's important to remember that batteries. Do not generate their own energy
And in order to make this a worthwhile endeavor
Renewable energy would need to generate a surplus of electricity during the day to charge them which California is already doing
everyday, California curtails
Significant amounts of renewable energy, which is not needed. This figure is continually rising with April
2019 having a record
190,000 megawatt hours wasted on May 7th of this month an astounding 8000
369 megawatt hours was curtailed
Nearly enough to fully charge our massive battery
It's this cheap energy our Moss Landing battery farm will be looking to purchase and sell for a profit
however going forward to May 15th just
193 megawatt hours was curtailed even in summer
Our renewable resources are highly variable and unreliable
This leaves us vulnerable
If we do not have alternative energy sources like natural gas or nuclear to pick up the slack
but let's move forward assuming we are going to rely on solar as Californian politicians seem to be aiming for
This requires billions of dollars to be spent building redundant power which can pick up the slack when needed this problem becomes
Particularly apparent in January in December where our energy generation falls off a cliff even in sunny, California
Let's analyze the towpath solar farm to see the scale of our problem in order for solar energy to reliably provide power
We need to size it to give us the necessary power even in winter months
once again
We've all the data we need to figure this out here is the average energy output for a single day of each month
over the past four years of this farms operation as
We can see our energy generation drops from a peak of four thousand three hundred and eighty eight
Megawatt hours in June to a low of two thousand six hundred and thirty seven megawatt hours in January
This differential is actually quite good and other solar farms can see a larger drop in production
But for now, we will be generous
So to charge our eleven thousand two hundred megawatt hour battery using this power source in winter. We would need a solar farm
4.25 times bigger than topaz firm this solar farm costs 2.4 billion to construct
So once again scaling linearly, we could expect a cost of 10.2 billion for solar farm of this size
Now this presents a new problem at our peak power in summer
We are generating on average an excess of seven thousand four hundred and thirty seven megawatt hours a day
if this energy cannot find a home grid operators have to shut it down to prevent it from
Overloading the grid to prevent the energy being curtailed it can be exported
Assuming neighboring states are also not over producing or we can add more storage to the grid which would cost roughly
3.2 billion using the same method of estimation from earlier
You can see a pattern emerging here to increase solar. We need to add more batteries in order to add more batteries
We need to add more solar and it eventually gets to a point where batteries dominate costs
Caused explode as we increase our reliance on renewable energy and storage
Here to just increase our renewable resources by 1.9 to maybe 2.5%
We have reached a total estimated cost of eighteen point two
six billion dollars
Four point six billion more than the construction cost of Diablo Canyon nuclear power station while producing less power
These costs bloat more and more as we increase our reliance on renewables in
Order to ensure we have enough power in the winter months
We have to build excessive amounts of renewable energy sources
Or we can try to store the excess power from the summer months and save it for a rainy day
at which point our costs become dominated by batteries the clean air task force an MIT research group estimated that
California would require nine point six million megawatt hours of energy storage at 80 percent renewable usage and
thirty-six point three million megawatt hours of energy storage at
100% this is equivalent to twelve days and forty five days worth of energy storage
Respectively their rationale for this which is not clearly given in any of their documentation, but I managed to track down the original
researcher is
this is the storage required to store all the excess energy in the summer months when we scale our
Renewables to be fifty percent from solar and fifty percent from wind while not scaling their power generation to provide enough energy
Even on the average winter day a very strange approach considering lithium-ion batteries are not suitable for long-term storage
Gradually losing their church
This coupled with the costs associated with batteries along with the rapidly falling price of solar and wind energy
Makes me very skeptical of the number
thirty six point three million megawatt hours of energy storage if we gave a generous future adjusted price of one hundred dollars per
Kilowatt hour would come out at a price of three point six three
Trillion dollars more than the three trillion gross domestic product of California for 2018
This for me is an over simplistic approach
So let's set forth our own plan taking January of this year as an example
We are going to scale our power for this month as it's our worst case scenario
Downloading the data for every single day of the month
we can see the energy demand per day varying like so
now if we place our solar generation on the same graph
we can see it generated an average of 8.2 percent of our total generation with a low of
2.1 percent on January fourth and a high of twelve point seven percent on January 27th
We had consecutive bad days on the 14th 15th 16th and 17th with only two point one to point two
five point two and three percent
From solar if we scale this to provide
100 percent of our energy needs even on our worst day we can see that the high variation would add
additional costs either in battery storage or excess solar
Thankfully if we now overlay our wind generation we can see that on those days
Wind generation was higher than normal and picked up the slack a little these were obviously cloudy stormy days in California
this raises an important point on California strategy
They have been rushing to install megawatts of solar in recent years and have not been installing enough wind
Wind maybe an overall more expensive power source for California, but going forward
It's going to be a vital part of diversifying their power sources if we add our other renewable power sources
Which are geothermal biofuels and small hydro facilities
Our new renewables count comes out like this accounting for an average of 20 percent of our energy needs
Large hydro facilities are technically a renewable energy source, but are not counted in our total as they require
environmentally destructive dams
They are also not counted as they are some of the oldest power stations and policy makers do not want large hydro facilities
Watering down their efforts in increasing other renewable sources for our purposes. This is silly. So let's add it in
Once again, we have smooth it our output allowing us to be less reliant on batteries and excess power
Closing nuclear stations is also a questionable move and overall going to add to our grids costs and inefficiencies
The higher the probability of dips in renewables on consecutive days like this the more batteries
We are going to need to store excess power on other days that also means we have to install additional
Excess power sources in order to ensure we have excess power to charge our batteries
This can be done in summer months. But as we said batteries are not well-suited to long-term storage
Thankfully many companies are working on developing cheaper energy solutions for the grid which will allow us to cost-effectively store energy
currently the true
Holy Grail is developing cheap storage that will be able to store all that excess power in the summer months and
Allow us to spread it out throughout the year
Arpa-e an energy research group modeled after DARPA the loonatics that funded this monstrosity
Invested 30 million dollars in 10 startups trying to develop this technology
some focus on thermal batteries others
Thermochemical and form energy who's developing a sulfur-based battery received the largest share of that 30 million
These are technologies that could facilitate a smaller more efficient renewable grid and we all cover them in a future episode
so to recap
California is heading towards over reliance on solar energy it needs to begin
Diversifying its renewable portfolio with wind and other sources
Continue to slowly build out these lithium-ion battery facilities to replace natural gas peaking power
But unless something dramatically changes
They aren't going to be a panacea to our renewable energy woes so continued research into low-cost
Long-term energy storage will be vital arpa-e needs to be supported in this effort
This is just a brief look at California
But while the parameters of this problem change with different climates and economies
The overall problem is the same
We need every country to be intelligently
Optimizing their grid to accommodate renewables to ensure an optimized grid is going to require careful
Analysis of historical data like we did above while calculating
Statistical likelihood of not fulfilling demand with different energy systems as much as I would love to
Performing a complete study of this nature is outside the scope of a YouTube video
but if I was going to do it
I would need to brush up on my Python coding knowledge to automate the process and my understanding of
Statistics both of which I could do on brilliant taking these two courses will give you all the skills
You need to take large data sets like this and make sense of them Python is one of the most widely used programming
Languages and it is an excellent first language for new programmers
This course will show you how to use Python to create intricate drawings
Coded messages and beautiful data plots while teaching you some essential core programming concepts
Combine this with the statistics course to learn more about medians variance and standard deviation
And you'll have all the skills to make sense of the mountains of data available on grid provider sites like this
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