|
|
Home |
Products | Smart Grid | Data | Power Factor |
Microgrid |
Support |
Factory | Art | Contacts |
| The Popular Smart Grid Idea: Data Intensive Monster español |
 |
|
The Motivation |
Top Down Design |
|
|
The public and the
governments are mandating that a Smart Grid structure
that integrates renewable energy be developed.
Their
goals are to decrease carbon emissions to the
atmosphere, reduce
dependence on petroleum (both foreign and domestic), decrease our use
of energy
and increase energy security for the population.
The policy makers do not have a firm grasp
of the physical realities of what they are asking of the grid companies. EPRI estimates this Smart Grid will cost $165
Billion and take 20 years to install. The
current plan for the Smart Grid has no
autonomous energy security for the office or home. |
The Smart Grid was conceived by
people at the top so it is a Top down strategy.
To implement this Top Down strategy the information at the local level
has to be minimized. Minimizing the
information locally means the system can never be very smart locally
and so has
to depend on the Control center making real time master
decisions. Real time decisions involve detailed data
being sent all the way to the
central control center and then back to each device. This idea
depends on an extremely complicated
high speed communications network that is a combination of HAN,
FAN/AMI, WAN
& LAN (the blue dotted lines).
The
software to manage
this amount of data processing will be cumbersome and introduce major
new
security risks. |
|
| The
Grid Company’s Dilemma |
||
|
Many of these concepts were
presented at the EPRI Power Quality and Smart Distribution 2010
Conference in Quebec in June of 2010. View the powerpoint presnetation here. The Typical Home uses an average of 1.7 kW It has 100 amp service which equals 24 kW So what are we designing, a system for 1.7 kW houses or one for 24 kW houses? A block of 100 houses needs 170 kW average. It has a possible peak of 2.4 MW. Typical load varies between 100 kW and 270 kW. Imagine a world where the houses used a flat 1.7 kW with no dynamics. Imagine a world where Renewable Energy was integrated into every home driving the grid load to a flat 1.2 kW still with no dynamics. This is the REAL SMART GRID. There is a driving need for autonomous energy security. |
Electricity is mostly
billed by
the kWh. However, the cost of providing
this energy is based on many things, including these heavy dynamics of
the
system. In other words, the Grid
companies are operating a business where their clients are not billed
according
to the costs. They have somehow managed
to operate this way for years. Now, the
public, the government and lots of scientists are telling them that
they need
to encourage their clients to use less energy. This
means they are told to introduce a marketing program
that reduces
their sales. In addition, they are told
to promote compact fluorescent lighting, which further reduces the
lighting
component of their sales by a factor of 6 to 1. On
top of that, the CFL lights have a power factor of .53
which means it
costs about twice as much per kW to provide the infrastructure to power
those
lights. In addition to increased
infrastructure cost the low power factor means there is an increase in
transmission loss which the grid company has to make up for at its own
cost. Usually, the total grid transmission
loss is
about 12% which means, in the case of .53 power factor CFL’s, that they have to
burn 31% more coal (at their own cost) just because of the power factor. Computers generally have a power factor of
between .6 and .7 meaning they have to burn 13% to 18% more coal. Then, they are asked to integrate Renewable
Energy
like solar and wind and told to double the accounting load as they keep
track
of buying and selling RE. Since the
solar and wind output varies with the weather and time of day, as these
become
significant, the Grid has to absorb the cost of managing these added
dynamics
which usually means adding more peaker plants. (Peaker
plants are essentially jet engines with electrical
generators
attached to them, usually about 50 MW) The
peaker plants are the most expensive way to generate
energy, they
burn hydrocarbons, pollute and are really going in the opposite
direction of
what was driving renewable energy in the first place.
In addition, as a first step towards
implementing the Smart Grid, they are encouraged to install smart
meters in
every home and office. So, as the Grid
is asked to lower sales, while increasing costs, they eventually pass
some of
these costs on to the customer. What the
customers see is they get a smart meter and the next thing they know
their
power bill goes up and they start to develop a bias against the Grid
companies. The Grid companies need a new business plan where they gradually lower sales but lower their costs enough so that their profit increases. |
|
The Real Smart
Grid (One House at a
Time) |
 |
|
This typical house system
includes 4 kW of power modules
which power 4 kW of critical loads like lights, refrigerators,
electronics and
UPS loads like computers. The power
modules are also connected to a solar array, a battery bank and to the
AC
grid. The T13X is a
smart load controller that connects to six
of the larger loads like the air-conditioner, hot water heater, pump or
electric vehicle charger. The T13X also
monitors the entire house grid connection. The
fact that the house averages 1.7 kW indicates that you
don’t really
have to run all of the larger loads at the same time.
The T13X manages which of the larger loads
are on and can guarantee that the total grid current is never above 50
amps. This would allow for cutting the
grid service to the house from 100 amps to 50 amps which actually cuts
the cost
of the electrical infrastructure in half. |
|
There is a remote panel that gives the
status of everything
and includes communication to the computers in the house and connects
to the
grid and other houses in the neighborhood for coordinated energy
management. There is full oscilloscope level analysis of
the grid, the six larger loads, the 4 kW of critical loads, the solar
panels
and the batteries. The idea is to have
the logic coordinate everything connected to the system for the maximum
benefit
to the owners, the community and the grid.
When the grid fails, the house can run the 4 kW of critical loads from
the 6 kWh battery bank combined with whatever solar power is
available.
This will normally run the critical loads for
an entire day and could run the essential loads from the daily solar
power indefinitely. This autonomous capability is the key element
of energy security.
|
|
Typical
House or Office System (One House at a Time) |
||||||||||||||||||||||||||||||||
|
|
Impact of 100 House Project |
|
Reduces energy consumption
by 20% saving over 23 MWH /
month. The smart load controller takes advantage of
the hours of the day when the house is unoccupied and reduces major
loads by
rules and schedules set up by the end user. Produces 27.6 MWH solar
power /
month
(Colorado)
making a total reduction in power drawn from the grid over 50.6 MWH /
month. Solar can be expanded up
to 60 MWH / month. This
can be added at any time at the customer’s option.
The idea is to involve the customer and
demonstrate the daily realities of their energy picture which
encourages their
involvement and provides an easy path for expansion. Automatic
surge assist to grid of 400 kW. When
inductive motors
start they require a surge of several times their normal operating
current. Occasionally, a lot of these
motors start at the same time and this requires the grid to have
substantial
reserve capacity to handles these surges. If
they do not have enough reserve power active, on line,
at the moment
of the surge, then the grid voltage sags which causes the inductive
motors to
draw even more current and the grid crashes. The
Transverter power modules automatically supply surge
power from the
battery bank. This entire surge
operation usually only lasts for a few seconds and so has a negligible
effect
on the energy stored in the batteries or on battery life.
Automatic power factor correction to grid of 400 kW. Electronic loads like computers and
compact
florescent lights do not take current from the grid in a smooth sine
wave but
take it in very sharp spikes. This phenomenon
is measured with a number called power factor which is the amount of
the
electrical infrastructure, including the power generators, that is
actually
usable. CFL lighting has a power factor
of about .5 and computers have a power factor of between .6 and .7
meaning that
these items only can use between 50% and 70% of the electrical system’s
capacity. The Transverter power modules
correct for this power factor locally so that the grid only sees a
power factor
of 1 (unity power factor) and so has 100% use of their infrastructure
and
generator capacity. The 4 kW power
modules in each house are more than enough to compensate for all of the
CFL and
computer loads in one house. This has a significant impact
on the total
grid transmission loss. In the case of
CFL lighting, the Transverter’s power factor compensation cuts the
grid’s load
by 13% just be reducing transmission loss. |
|
100 amp
service → 50 amp service. The automatic
load controller combined with the automatic surge assist guarantees
that the
grid current never exceeds 50 amps. This
allows actual downsizing of the entire electrical service to the house
including all of the wires and the transformer.
This, by itself, does not reduce the average
amount of power the grid is providing to an area but it absolutely cuts
the
cost of the local infrastructure (the actual transformer and wires that
connect
the house to the grid) in half. It also
protects the grid from the freak coincidence of a whole bunch of houses
having
all of their 100 amps of service loads come on at the same time. Community
Energy Storage capability. The
total battery capacity of the 100 house
project is 600 kWh which is
significant. By setting rules that
balance the individual needs with the grid needs this can be used to
reduce the
dynamics the grid has to handle. This
reduces the use of peaker plants and (with enough systems) could
eliminate
their need altogether. Individual
home energy security. Each home can operate
autonomously when there is a grid failure. The
6 kWh of batteries combined with solar will power the
critical loads
for a typical day and could power essential loads like refrigeration ,
lights,
communications, etc. indefinitely. The
social impact of most houses and small offices having this capability
in a disaster
like Katrina would be enormous. Real time
information and datalogging. The
remote panel
gives all of the important energy information to the users so they
always know
the true balance of their energy usage and capabilities.
This interfaces to their computers for more
in-depth graphical analysis and control and can communicate to other
houses
nearby and to the grid to coordinate energy decisions and priorities. The automatic datalogger documents the
effectiveness and ROI of each individual house and, when combined, of
the
entire project. Turns the
whole project into a laboratory. Each
circuit of each
house creates detailed mathematical models of everything in the system
and can
communicate these either in real time or as summaries to the research
and
development labs of anyone designing batteries, solar panels, smart
grid
systems or anything in the electrical power sector.
This will be an enormous free stimulus to
developing new energy solutions Who pays
for all of this? There
is a PACE financing system already
active in many states where loans are made for systems reducing energy
taken
from the grid by over 20%. These are
added to the value of the house and paid back through increased
property
taxes. That way it does not involve the
person’s
individual credit and automatically goes with the house if the house is
sold. Because this system delivers so much
value to
the grid, the individual and the community, creative financing schemes
could
emerge where all three entities share the burden. |
 |
|
This is a graph NREL made
to demonstrate the power use for an
entire grid sector for one day. The red
line is the forecast wind power based on the previous day’s performance. The black line is the actual wind power that
was provided. Xcel Energy (a major grid
provider in the Midwest) has put notes listing all of the ways it costs
them more
money, both when the wind puts out more than expected, and when it puts
out
less. Notice that when it puts out less
they list greater peaker plant costs. The blue arrows are for
scaling this to one house. You can see
that the biggest peak in surplus
wind power is only 323 watts. If the
Transverter power modules automatically charge the battery when there
is
surplus wind energy and discharge the battery when the wind is less than expected then it would only
require less than ½ of a kWh to
totally neutralize the wind’s fluctuations and completely remove all of
Xcel’s
extra costs. |
|
This is only cycling 8% of
the battery’s capacity and doing
it at rates under C/19 which is totally feasible for gel cell lead acid
batteries and you could expect very long battery life. Also, notice that a lot of
the peak hours are at times when a
house is the most likely to be unoccupied while people are at work. This is when the smart load controller could
have its maximum impact. Also, notice
that between 7:00 pm and 7:00 am there is not so much power drawn which
would
be an ideal time to charge electric vehicles. |
|
Community Energy Storage
(One House at a Time)
|
 |
|
This picture has lithium
ion batteries that use
cells that are identical to the ones being developed for electric
vehicles. They have special embedded
electronics to enhance performance and reliability and have a
demonstrated life
of over 10,000 cycles. They are
currently available for about $1,000 per kWh but, as the electric
vehicle
market evolves, their price should come down to $500 per kWh or less. Currently, high quality lead acid gel cells
are about $250 per kWh. |
|
As a point of reference, the Chevy Volt
plug in
hybrid has 16 kWh of Li-ion batteries. This
picture is from a community storage installation in San Francisco done
by Growing Energy Labs. The
Transverter
power modules are based on mathematical models of the batteries and can
automatically adapt to any chemistry of battery available today or any
type of
battery that will be developed in the future. |
|
Balancing Loads with
Solar
(One House at a Time)
|
|
This is the same 24
hour load profile from the previous NREL graph with it scaled to one
house. We have calculated the optimum
size of solar array to help balance this use pattern (in this case 1.84
kW of
solar which is 8 of the 230 watt panels. You
can see the difference between what is used in the
house and what is
produced by the solar with the green line. If
we charge the batteries when the green line falls below
the average
and discharge when the green line is above the average then the net
effect to
the grid is the completely flat line of the average.
Aside from alleviating the burden of using
peaker plants to deal with peak loads this has a significant effect on
grid
transmission loss which is usually about 13%. Just
adding this solar (without the battery balancing)
removes 11% of
the transmission losses and the solar combined with the battery
balancing
reduces the grid’s transmission losses by 57%. This
would only require communication with the grid once a day. This
requires daily
charge-discharge cycles of 3.9 kWh which is clearly out of the range of
what
you can realistically expect from lead acid batteries but is totally
reasonable
for the Li-ion batteries. This would add
$4,500 to the cost of the system at today’s prices but that should drop
to
about $2.000 in the near future.
|
|
Daily
Charge-Discharge 3.9 kWh = 65% of 6 kWh battery This
totally achieves the
dream of the ideal house with the constant average power drawn from the
grid
with no dynamics. All this without selling
any power to the grid or any equipment outside the house. |
|
This is a similar graph
for the entire state of California for last July 8th. It has been scaled for one house.
The optimum solar array to balance this load
profile turns out to be 920 watts which is exactly half of what is in the
example one
house system described earlier. Just
adding this solar (without the battery balancing) removes 6% of the
transmission losses and the solar combined with the battery balancing
reduces
the grid’s transmission losses by 31%. This
example has 15% of the energy coming from solar.
This, when combined with the renewable energy sources the grid
already has, would make California’s goal of 20% renewable energy easily
obtainable. Again, the discharge
cycles are similar which mandates going to Li-ion batteries. There are no projects
proposed which have anywhere near this level of impact on the cost of
providing
electrical power to houses and offices. This
is all done with a minimal of communication to the grid, no special
billing or
permits and nothing installed outside of the home and office. |
|
Daily
Charge-Discharge 3.7 kWh = 62% of 6 kWh battery |
We can implement many of
these 100 house test
projects immediately. Each project will:
|
|
What we
are proposing is the real smart grid, one house at a time, providing
autonomous
smart nodes, implementable today, integrated Renewable Energy, demand
response,
data acquisition, advanced metering, end to end communications, power
quality
control, energy security, community energy storage, a living system,
evolving
and adding applications over time. There
is nothing else that has been proposed which comes close to these
benefits,
particularly considering that this can be implemented immediately for a
minimal
cost that can easily be financed. Help support this project by going to the GE Eco Challenge and registering and voting. For concrete examples of
real systems go to Microgrid and |
|
Home |
Products | Smart Grid | Data | Power Factor | Microgrid |
Support |
Factory | Art | Contacts |
