Day in, day out you are using one of the biggest machines in the world and may not even know
it.
It’s in your home, it lines the streets and it’s powered by gigantic engines across
the country.
The biggest machine in the world isn’t this, or this, or even this.
It’s the electrical power-grid or more specifically the US power grid.
In the United States alone the grid contains enough high voltage wiring to wrap around
the earth 6 times over and that’s not including all the low voltage wiring running through
our streets and into our homes.
This entire system was built in a little over 100 years and since then we have become very
accustomed to having electricity available to us at the flip of a switch, but before
this machine existed our only sources of light by night were lanterns and candles and nearly
all our daily chores needed to be done by hand.
This giant machine started pretty small with the world’s first central power station
built on Pearl Street, Manhattan in 1882.
Thomas Edison, the ever present American businessman, saw an opportunity to not only sell more of
his lightbulbs, but to sell the electricity to power to them.
So he built an electric generator driven by a coal powered steam engine to create electricity
at a cost that would allow his light bulbs to compete with lanterns.
The station contained 6 of these generators each produced 100 kilowatts, enough to power
1200 of edison's lightbulbs, allowing edison to sell 7200 lightbulbs, which needed to be
replaced regularly, as these early bulbs lasted about 1200 hours.
Even then the project ran an operating loss for it’s first 2 years.
Setting up this system was a bold business move.
The machines, the conduits and the 30 kilometres of wiring needed for it were expensive at
a cost of 300,000 dollars or about 20 million dollars in today’s money.
The expensive Lower Manhattan real estate didn’t help either, but Edison’s placement
of the Pearl Street Station was vital to the success of his idea, as it had the population
density to make the project financially viable, but he also made one of his first customers
The New York Times.
Who published a story about the historic event, reporting that the light was “soft, mellow
and graceful to the eye…without a flicker to make the headache.”
This was all the marketing Edison needed and demand for the system grew, but this pointed
out one of the systems major flaws.
It couldn’t scale economically without installing more power stations nearby, because it generated
a low voltage direct current and to efficiently transfer power over long distances we need
to transform the low voltage to a higher voltage.
The power loss equation states the power lost in transmission equals the current squared
multiplied by the resistance of the wire and so to reduce power loss we really need to
minimise the current.
This equation describes the relationship between power transmitted and the voltage and current.
The community demand fixes the amount of power required and so to decrease the current we
need increase the transmission voltage.
Alternating current’s main advantage over direct current isn’t that it loses less
power over long distance, but that it can be transformed from low voltage to high voltage
much more efficiently than direct current.
Thus as demand for power grew across the nation the famed argument between Edison’s idea
to have many smaller generators located near population centres and Nicolas Tesla’s idea
of having one large efficient engine located far from population centres grew.
Of-course we know who won and today we have hundreds of gigantic power stations located
far from population centres generating gigawatts of power.
So what would a map of the current US electrical grid look like?
Let’s create a map showing the largest power plants across the US.
In areas where rainfall is high like Washington state on the west coast and Alabama in the
south there is a high volume of electricity generated with hydropower.
Where wind speeds are highest in central America there is a growing number of wind turbines
and states that get the most sun like california and Arizona have the highest percentage of
solar power, there are several high power nuclear power plants located in areas where
water is plentiful, which is needed for the steam turbines and to cool their cores.
Coal power plants tend to be close to coal mines as its a very heavy fuel, but The largest
percentage of energy in the US is generated from natural gas, as it is the cleanest of
the fossil fuels.
Let’s zoom in on one of these power plants to get an idea of how this energy is delivered
to population centres.
As I mentioned earlier it is vital that electricity is transmitted at high voltage, so the first
step as the electricity exits the power plant is to pass it through a step-up transformer,
the electricity is then delivered across these high voltage power lines that you see stretching
across the country.
These power lines feed into local step-down transformers for local distribution in neighbourhoods
and gets stepped down again by these transformer drums on poles outside your house.
The electricity you consume in your home is measured on a meter like this that reads the
power running through the wire that enters your house.
So let’s say after a long day’s work you come home and decide you want to watch the
premiere episode of Game of Thrones.
You plug in your viewing device of choice and that meter starts to tick a little faster,
along with millions of other meters across the nation.
Suddenly the biggest machine in the world just got a little bigger and the engines powering
it have to work harder to keep up with that demand.
This is one of the huge disadvantages of the current power-grid.
During low demand hours we have a number of always on power plants called baseload plants,
that are powered by reliable energy sources like coal and nuclear.
These maintain the baseload requirements of the country, but what happens if one of these
power stations fail?
Suddenly the system doesn’t have enough energy to meet demand and if we don’t have
the ability to meet it power stations will begin rolling blackouts where they cut the
electricity to certain areas to prevent a larger blackout.
One of the largest of these rolling blackouts to ever occur was the 2003 north-eastern blackout
that left 50 million people without electricity.
Rolling blackouts like this should usually never occur in a country as advanced as the
US.
Modern countries will have many redundant power sources that can be brought online when
power demand surges or power stations go down and excellent communication between all parts
of the grid to ensure problems can be fixed immediately.
But as renewable sources like wind and solar become more popular this micro-management
of the power-grid is becoming even more difficult.
We cannot command the weather to make these power sources work harder when needed and
the more likely scenario is that we have to shut down these power sources while they could
be generating energy, because they are generating energy that is not needed, which can overload
the system.
It’s unlikely that we will be able to rely on renewable energy without still having many
baseload power plants running on natural gas, coal or nuclear, unless we create an efficient
way of saving this energy during peak performance for later use when the demand is there.
Currently the largest energy storage method worldwide is hydro-electricity at about 80%.
On some days of the year Denmark generates so much energy from Wind that they have enough
to export to countries like Norway, who often use the advantage of their mountainous terrain
to buy this cheap excess power to pump water to the top of mountains.
This water can then be released to power hydroelectric turbines when it’s needed.
Of-course this leads to some power loss, but it is better than shutting down the wind turbines
while they are at peak performance.
This issue is only going to grow as solar energy becomes more and more popular, which
is why Tesla’s Powerwall is such an integral part of making widespread home installed solar
power a reality.
If we cannot store the excess energy generated by these panels during the day, for use when
there isn’t sunlight, then we are still going to depend highly on those baseload power
plants using fossil fuels or nuclear energy.
As the price of manufacturing solar panels decreases it is inevitable that all countries
will begin to move away from the current model of the powergrid.
We are at the brink of world changing moment and the largest machines in the world are
going to drastically change for the better.
Large fossil fuel power-plants generating AC electricity are quickly becoming out-dated
and will be gradually decommissioned over the next couple of decades and a new model
for the power-grid will rise in it’s place.
We will be gradually moving towards Thomas Edison’s early vision of having many local
low voltage power generators creating DC power, but with a modern twist.
They will all be powered by nothing more than the energy we can draw from the ever replenishing
pool that nature has provided us.