of smart appliances and consumer devices
Right now, power
plants and distribution systems are designed to be able to respond to the
highest potential demand. That fact together with an increase of the demand due
to electromobility of around 20-40% makes the whole system highly inefficient
and costly. Therefore, a strategy is needed to reduce or shift energy consumption from peak hours of the day to
other periods of the day, when the grid is underloaded. That would allow to
lower peak demand during demand intensive periods of the day and help reducing
the overall distribution and generation cost, as well as mitigate potential
To carry this
strategy through there would be two different approaches:
The first one would require that the customer
decides which activities are non-essential, so they can be arranged at another
time when the load of the grid is lower. In that case, a compensation method
must be found to motivate the customers to shift their consumption to lower
demand periods. Such as an incentive would be cheaper electricity.
The second approach would be to create a
system with slots of energy in with the smart appliances get registered in the
system and apply for a certain amount of energy slots. Somehow similar like in
a telecommunications system, where the users ask for permission to transmit but
in this case the loads ask for permission to consume.
from that, a proper way to automate these events must be implemented which
enables direct load control. Because
it shall include the remote interruption of energy consumption of some
non-essential loads, like heaters, cooling systems, charge of electrical cars
or washing machines, just to mention a few.
topic that has already been introduced in dynamic
pricing, which depends on lot of factors not only current consumption and
type of consumption, but also weather forecast for sun and wind in the areas of
the wind and solar plants. The gap between expected electricity generation and
expected demand needs to be filled up with other sources like hydraulic plants.
And the bigger this gap the more expensive shall be the electricity.
Another alternative to
reduce greenhouse gas emissions and increase the individual consciousness would
be to introduce for every customer a gas emissions counter. Which depending on
their energy-consumption behavior would increase or reduce the taxes accordingly.
That would encourage consumers to adopt load-shedding and load-shifting solutions
that actively monitor, and control energy consumed by appliances.
So, the mains
challenge to perform the strategy is a to develop a standardized communication
system that allows electricity providers and consumers to exchange real-time
information. That should include the possibility to define several
non-essential loads, which are directly controlled by the provider to enable
cost-effectively meet growing energy demand.
Till a few years ago,
it was thought that electricity cannot be stored and needs to be consumed
directly after generation. However, storage technologies and solutions have
been developed a lot in the last years, what is making viable the electrical
energy storage. That allows that the electricity production does not need to be
drastically scaled up and down to meet momentary consumption. There are already
globally around 202 GW of grid connected to storage systems. Here we present
some of the methods available:
hydroelectric energy storage (PHES)
It is the most
successful method due to the fast response and storage capacity. This method
stores energy in the form of gravitational potential energy of water. The water
is pumped up with the surplus electrical power and during periods of high
demand, the stored water is released through turbines to generate electricity.
The conversion efficiency is around 75% but it helps to cover the demand during
the peaks. Apart from that, it complements the generation of energy from
intermittent sources, such as solar and wind, because it helps to store the
energy during low-demand peaks that in worst case would not be used at all. In
addition to that, the short-term prediction of wind generation is a big issue,
so PHES offers a huge help to cover the demand and makes use of the possible
surplus of the wind farms.
Due to the
development of the electric vehicle the production cost of batteries decreased
below $300/kWh and it probably go under 150$/kWh by the end of the 2020. Battery
storage technology based on an electrochemical basis (such as Sodium-Ion or
molten-state) and is typically around 75-85% efficient. In 2015, a 221 MW
battery storage was installed in the USA, with total capacity expected to reach
1.7 GW in 2020. (http://reneweconomy.com.au/us-energy-storage-market-grew-243-in-2015-largest-year-on-record-61611/).
However, there are still on the early stages of development, so huge progress
is expected within the next years.
vehicles can also be used as a storage system. They can be used to relieve the
grids during peak demand hours and charge again mostly during nights, when
grids are underloaded. However, these batteries rely on a Li-Ion technology,
which is suited for mobile applications (high cost, high density).
This method works by
accelerating a rotor to a very high speed and maintaining the energy in the
system as rotational energy. Such a system typically has rotors made of high
carbon-fiber composites, which is suspended with magnetic bearing and can reach
between 20.000 to 50.000 rpm inside of a vacuum enclosure. This method allows
to store electricity much faster than other forms of storage. A rapid charging
of a system occurs in less than 15 minutes and the energy efficiency of the
system can reach 90%. In comparison with other energy storage solutions the
flywheel is characterized by its long lifetime with very little maintenance.
Therefore, they are
typically used to overcome short peak demands locally. Typical capacities range
from 3 kWh to 133 kWh.