LEED Home

The previous home was modified to reach a LEED Gold Rating. Changes to the home include: increased outer wall thickness, addition of blown-in cellulose insulation above the ceiling, upgraded windows to achieve required U -value, addition of insulation below the concrete slab, energy star appliances, and high efficiency fixtures. The fallowing LEED certifications will be achieved:

To meet the LEED certification, special fixtures, appliances, and lighting have to be purchased. These products are more expensive than the average products you may find in a normal home. It will cost approximately an extra $1000 to meet these LEED requirements. The LEED home will save approximately $120 a year on electricity and water bills. The payback period is 8.3 years. Items that must be upgraded are:

The load calculations were performed as before and the resulting heating and cooling loads were used to select the proper geothermal unit. The LEED home will require the use of a 24,ooo Btuh geothermal unit. The ground loop temperature as well the condenser and evaporator temperatures were estimated through system simulation in MatLab. The following results were produced:



The operating cost of the LEED home heating and air conditioning was calculated and is listed
below:



To determine the benefit of the LEED improvements, the payback period for the LEED improvements was estimated alone and then was combined with the geothermal cost and savings to give a combined payback period for the geothermal and LEED improvements.

Payback Period = 37 years

The combined payback period was then estimated and is shown here:

Payback Period = 24 years

Basic Home

A 1000 Square foot house was designed using geothermal for the heating and cooling system. A load calculation was performed and includes losses through windows, walls, ceiling, and floor. The house will be built as a slab on grade. The house has a footprint of 25 x 40. The walls are 8 foot tall. The house will first be designed and analyzed using basic construction methods.

Basic

The walls will be constructed using 2 x 4 lumber and batted fiberglass insulation. They will have 1/2 inch plywood sheeting on the exterior along with vinyl siding. On the interior, the walls will be covered with 1/2 inch drywall.

The ceiling will be constructed using 5/8 inch drywall on the interior along with batted fiberglass insulation between the trusses.

The floor will be constructed using 4 inch thick medium concrete. For the load analysis, only one dimensional conduction will be considered.

Inexpensive windows were selected for use. These windows are not energy efficient. They will be Pella Thermastar windows.

The materials used in the construction of the walls and ceiling were combined in an appropriate manner to determine the U -Value. The table below shows the materials individual U values based on thickness and thermal conductivity.



The materials were combined to obtain an overall U value as shown:



These U values were used along with the exposed areas of each and the design temperature difference for both heating and cooling to obtain total loads for heating and cooling. The results are shown below.



Using the calculated loads, a geothermal system was designed. The geothermal unit, comprised of the indoor and ground loop heat exchangers, the blower, and the compressor will be provided from GeoComfort. The unit will need to be 36,000 Btu nominal rating to handle 80% of the heating load. The performance characteristics given by the manufacturer were used to determine the COP, EER, and necessary flow rates for both the air and the ground loop fluid. The general circuit for the geothermal unit is shown here:



The ground loop was designed using 1" black plastic pipe. The length was set to 150 meters per loop using three loops total. The flow rates and heat extraction of each loop was assumed to be equal. The effectiveness of the ground loop was determined by treating it as a simple heat exchanger where the ground temperature, and therefore the outer wall of the pipe, would be maintained at 50 deg F. The effectiveness was calculated as being equal to 0.90.

Equipment Selected:

Geothermal unit - GeoComfort 036C

Ground Loop Pump - Grundfos UPS 15 - 58F/FC




The nominal output of the geothermal unit during heating includes the work done by the compressor and the work done by the ground loop pump. To get an accurate estimate of the steady-state ground loop temperatures, evaporator and condenser temperatures, and ground loop heat transfer, a simulation was created in Matlab. The following diagram shows the basic layout of the overall system:

The value of q cd was assumed to be the known output of the unit. The return air temperature is taken as the house temperature. The ground temperature is a known value.

Unknowns: T supply, T cd, T ev, T3, T4, T5, q ev, qcd

Knowns: T house, T g, q cd, W pump, COP, Ca, Cf, effectiveness of ground loop, effectiveness of evaporator, effectiveness of condensor

Eight equations were developed and were iterated using MatLab. The results of the simulation are shown here:



The cost of operation of the Basic Geothermal Home was calculated using the air exchange rate for the home and the applicable heating and cooling degree days in Iowa. The results are shown here and compared to the operation of a conventional HVAC system that employs a Natural Gas Furnace and split type Air Conditioner.










The payback period has been illustrated for the geothermal system using the upfront difference in cost and the operational savings per year. The following plot indicates the number of years of operation to payback.

Payback Period = 16 Years

Carbon Footprint

Assuming that the energy used in Iowa City comes from Coal a normal air-forced heating and cooling home uses 5.25 tons of CO2 on electricity and Gas.  A LEED home only uses 3.88 Tons of CO2.  These numbers are calculated by assuming that each kWh of electricity creates 2.25 pounds and each kWh of gas creates 1.95 pounds of CO2. 

The LEED home saves 1.37 tons of CO2 per year

LEED - Leadership in Energy and Environmental Design

LEED stands for Leadership in Energy and Environmental Design.  LEED is an internationally recognized green building certification system.  LEED is a certification that a building or community was designed and built while considering 5 key areas: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.  LEED-certified buildings are designed to: lower costs and increase asset value, reduce waste sent to landfills, conserve energy and water, be healthier and safer occupants, reduce harmful greenhouse gas emissions, and qualify for tax rebates, zoning allowanced and other incentives in hundreds of cities.  When a LEED certification is processed the Green Building Certification Institute (GBCI) is a third party that will rate the development.   The building will receive a rating in each of the five key areas and can receive bonus points for innovation in design and regional Priority.  The 5 categories individual points are based on their individual impact; however the total points possible are 100 with an additional 10 for the bonus.  If a building receives 40+ points it is certified.  Going above and beyond a building or development can obtain a Silver, Gold or platinum rating all dependent on its final LEED Score.

LEED has 8 different categories that a building could be certified in: new construction, existing buildings, commercial interiors, core and shell, schools, homes, retail and neighborhood development.  The core-and-shell construction is applied to a large building with a long lead time.  The shell is designed first and built.  Then as the shell is being built the core is designed and implemented once the shell is finished.  This type of construction cuts out some of the down time for designing.  The core designing can be done while the shell is being built.

Looking at the core-and-shell project profile for the Banner Bank Building you can see the impact LEED can make.  The Banner Bank Building is a 195,000-square-foot, 11-story Art Deco building in downtown Boise, Idaho.  The Banner Bank Building has a Platinum LEED rating and uses 65% less electricity, 80% less water, and has a 32% return on investment.  It has implemented an innovative system that Captures storm water from downtown Boise streets and parking lots. The storm water, along with reused gray water from the building itself, is used to flush all the toilets and urinals at the site.  The Banner Building also uses a geothermal system for heating and cooling, light sensors, and the HVAC system supplies a high number of air changes per hour and monitors the carbon monoxide.  Even with the extra parts to be LEED certified the Banner Building still only cost $128 per square foot to make and it is so energy efficient that the tenants can be charged rent similar to buildings 20 to 30 years older.

The LEED Certification is a big step moving towards sustainability.  If in the next 25 years all the buildings built have this certification or one similar and work as well as the Banner Bank Building it will cut the energy and water use across the world.  I hope to see more innovative certifications like the LEED certification in the future.

Source:

www.usgb.org

Residential Energy Usage

This section of the blog will be dedicated to the analysis of the energy needs of a typical 1000 sq ft home in Iowa City, Iowa. The heating and cooling needs will be assessed on the basis of building materials, design temperature criteria, and internal heat gains.

Building Materials and Thermal Conductance

The R values of standard building materials are listed in the following table. The materials are used in various configurations throughout the house. The thermal resistance of the combination of materials was calculated. The U value for configuration was determined. The U value was multiplied by the area of each type of construction and the overall thermal conductance was determined.

Material	Thermal conductivity (W/m K)	Thickness (m)	U value (W/m2 K)	R Value (m2 K/W)	R Value (ft2*F/Btuh)
Plywood High Density 0.5"	0.08	0.0127	6.30	0.16	0.90
Plywood 0.5"	0.17	0.0127	13.39	0.07	0.42
2 x 6 Stud 5.5"	0.1	0.1397	0.72	1.40	7.94
Fiber Glass Insulation 5.5"	0.038	0.1397	0.27	3.68	20.89
Drywall 0.5"	0.17	0.0127	13.39	0.07	0.42
Drywall 0.625"	0.17	0.015875	10.71	0.09	0.53
Vinyl Siding 1"	0.1	0.0254	3.94	0.25	1.44
Brick 3"	0.7	0.0762	9.19	0.11	0.62
Polystyrene 2"	0.03	0.0508	0.59	1.69	9.62
Medium Concrete 4"	0.5	0.1016	4.92	0.20	1.15
Shingle 0.625"	0.75	0.015875	47.24	0.02	0.12
Blow in insulation	0.045	0.254	0.18	5.64	32.07

Area of one window	12
Number of windows	8
Gross Wall area	1040
Ceiling Area	1000
Window Area	96
Net Wall Area	944

Design Temperature Difference

The design temperature difference was determined as listed in ACCA Design Manual J. For heating, it has been determined that only 1% of the year it is colder than -6 degrees F. For cooling, it has been determined that only 1 % of the year it is warmer than 95 degrees F. These temperatures will be used with an indoor design temperature of 70 degrees F. The heating and cooling system will be designed to handle these situations.

Ventilation Rate

The ventilation rate for our home will be taken as 50% of the total volume per hour which is the worst case scenario listed in ACCA Manual J for loose construction. The household volume is calculated using 1000 sq ft and 8 foot ceiling heights. The load due to air exchange was calculated using the mass flow, specific heat, and temperature change.

Heating and Cooling Load

The heating and cooling loads were calculated using the design temperatures and thermal resistances. The cooling load was calculated using a 25 degree temperature difference. The heating load was calculated using a 76 degree temperature difference.

Energy Profile

Standard energy usages were determined for common household appliances. The energy consumption was compared to the energy use of the heating and cooling system through the use of a pie chart.

Appliances	watts	Btu/h
ceiling fan	50	170
Coffee Maker	200	680
Blender	300	1020
Garage Door Opener	350	1190
Refrigerator	540	1836
Computer	300	1020
Electronics	1000	3400
Microwave	1000	3400
Blow Dryer	1000	3400
Toaster	1000	3400
Dishwasher	1500	5100
Range	2000	6800
Washer/Dryer	4500	15300
Hot Water	4500	15300
Lights	1500	5100
Air Conditioning		15757
Heating		51290.88

Energy Efficiency

Energy efficiency is a topic that has been around for a long time. If company A and company B both make a TV and company A’s is more efficient resulting in the customer having to pay less to use it the customer will prefer their product. As consumers we can sum up value as what we pay for a product versus its qualities the product has. It would be nice for the consumers and for earth if the cheapest product was the most energy efficient however we know this is not the case. With that being said the trend of consumer products over time is that they become more efficient. For example from 2001 to today refrigerators use 40 percent less energy.

Our current energy crisis means that we are using more and more energy. We are making products that are more energy efficient however we are still using more energy. In order for our energy efficiency to help our energy crisis it must lower our consumption which it has not done. A big factor in this is the consumers need for material things. Although they are buying more energy efficient products they are buying more products. We can also contribute some of the energy to the advancement of electronics. We purchase electronics and a year later we are upgrading. This kind of trend result in large energy consumption by manufacturers making the products we buy. Because of the rise in energy cost we should see a leveling of energy consumption. Eventually cost will be so high that efficiency will become the number one priority. When this happens there will need to be innovation and engineering resulting in much more energy efficient products. As long as we can keep being innovative and engineer energy efficient products eventually we will see a change. Hopefully we will see energy consumption drop however it is possible that we see energy cost drop through innovation and out of the box engineering. If this happens we may shoot ourselves in the foot and cause an even larger energy crisis.

http://www1.eere.energy.gov/ba/pba/intensityindicators/total_energy.html

http://greenitinc.com/solar_vs_non_renewable_energy_costs_comparison

Sources:

(7) http://en.wikipedia.org/wiki/Cost_of_electricity_by_source

(8) http://en.wikipedia.org/wiki/Efficient_energy_use

(12) http://greenitinc.com/solar_vs_non_renewable_energy_costs_comparison

http://www1.eere.energy.gov/ba/pba/intensityindicators/total_energy.html

Carbon Sink

A carbon sink is described by Wikipedia as “a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period.” Examples of natural carbon sinks include rain forests, oceans and soil. Rainforests have large role in Co2 levels.

Rainforests at a young age will remove CO2 from the atmosphere, however a full established rainforest is actually carbon neutral and simple can store CO2. This is still very important to the carbon cycle because CO2 can be stored in biomass in the rainforest instead of in the atmosphere causing global warming. According to EPA statistics forests accounted for about 10% of the United States CO2 sequestered. Due to the Kyoto protocol which allows trade of carbon emissions and using forestry as an offset, forestry has grown and the United States is planting more and more trees. With this being said 1 million trees can account for 0.9 tetra grams of carbon dioxide removal. The United States released approximately 5657 tetra grams of carbon dioxide in 2004. These facts lead us to the conclusion that the physical loss of forests has not contributed much to our current CO2 state. In all actuality the regrowth of forest removal is probably helping us more than if the forests were still there. With that being said I do realize that forest removal does cost some amount of carbon because of equipment used to remove forests and the small consumption of carbon that forests do have. I think the end conclusion is that you cannot contribute CO2 gains to forestry loss. Building new forests to help offset our present CO2 crisis is not a practical solution. According to benefit of trees in urban areas trees can store approximately 2.3 tons of carbon per acre per year and the average person consumes about that same amount. This means each person would need their own acre full of trees to offset their carbon footprint. That doesn’t include dropping our current state but only considering breaking even.

http://nafoalliance.org/policy-issues/biomass-energy-advocacy-toolkit/

The ocean accounts for about ¼ of the earth’s CO2 natural sink, through the use of plankton and other biological processes. From Pre-Industrial to present day the oceans pH level has gone from 8.179 to 7.824. As the pH drops in the ocean multiple things happen. The first thing is that the animal life becomes less desirable and if it continues could cause massive issues for marine life. It also lowers the ability to capture CO2. Knowing that the ocean accounts for a very large amount of CO2 capture in the future we could see a even higher growth in CO2 if the pH continues to rise. With that being said the reduced the amount of CO2 that it takes in it is simply becoming saturated. That means that the CO2 crisis we are in now cannot be contributed to the oceans pH but rather the other way around. The good news is that studies are being done that use the ocean to reduce our current CO2 state. Adding Iron to the water stimulates growth of plankton. It has been found that each atom of iron added could contribute to removing 10 to 100 thousand atoms of carbon. Unfortunately the repercussions to marine life are unknown and at this point more research must be done before this can be done on a massive scale.

http://en.wikipedia.org/wiki/Ocean_acidification

Soil is the other big contributor to natural carbon sinks. CO2 is stored in soil through organic matter, roots and biomass. It has been shown most recently that farming and tilling of land is releasing oxygen and lowering the ability for the earth’s soil to capture CO2. Unfortunately not a lot of information on previous abilities of the soil to capture CO2 is available. However it can be predicted that if farmers used different tactics with their land soil could contribute to removing 10% of our projected CO2 use. From this I think it is safe to say that while soil could contribute to a solution it is not what put us in the CO2 crisis we are in.

This blog has reiterated that the current CO2 crisis causing global warming is not due to natural occurrences. It is even more unfortunate to know that earth’s natural resources will not contribute what we need to remove the CO2 we presently have.

Sources:

(21) http://www.coloradotrees.org/benefits.htm#carbon

(5) http://co2now.org/

(10) http://www.globalcarbonproject.org/carbonbudget/09/hl-full.htm#naturalSinks

(4) http://en.wikipedia.org/wiki/Carbon_sink

(18) http://en.wikipedia.org/wiki/Ocean_acidification

Energy Efficiency

Energy efficiency is the goal of efforts to reduce the amount of energy required to provide products and services. An example would be installing fluorescent light bulbs because they reduce the amount of energy required to attain the same illumination as regular incandescent light bulbs. Compact fluorescent light bulbs use 2/3 less energy and may last 6 to 10 times longer than incandescent light bulbs. Improvements in energy efficiency are most often achieved by the use of more efficient technology or production process.

There are various motivations to improve energy efficiency. Reducing the energy cost may result in a financial cost saving for consumers. Reducing energy use is also a key solution in reducing carbon emissions.

http://en.wikipedia.org/wiki/Efficient_energy_use

What is a Carbon Footprint?

A carbon footprint is a measure of the impact that our activities have on the environment, and in particular climate change. The carbon footprint is also a measurement of all the greenhouse gases an individual produces. A carbon footprint is made up of two parts, the primary and a secondary footprint. The primary footprint is a measure of our direct emissions of CO2 from the burning of fossil fuels. The secondary footprint is a measure of the indirect CO2 emissions from the whole life cycle of products we use.

www.carbonfootprint.com/carbonfootprint.html

The figure above shows the main elements which make up the total carbon footprint of a typical person who lives in a developed country.

Embodied Energy

Embodied energy is defined as the sum of energy inputs that was used in the work to make any product, from the point of extraction and refining materials, bringing it to market , and disposal or re-use of the product.

http://www.tececo.com/sustainability.embodied_enery.php

The figure above shows the embodied energy of certain building materials. Concrete is at the bottom of the list because it requires a lot of energy to be made while an aluminum sheet has high energy output.

Feasible Energy Plan for The Netherlands

Now that the energy being consumed has been determined for The Netherlands and the theoretical maximum renewable energy has been estimated, a realistic energy plan can be developed. To start, a comparison of the Red and Green stacks should be made.


The total for the green stack is 167.2 kWh/d and the total for the red stack is 125.3 kWh/d. The red stack is slightly low compared to the energy usage given in McKay but will be used for the consistency of this analysis.

Offshore Wind

The leader in the green stack is offshore wind energy. This value is considerably higher than would actually be available due to the fact the calculation was done using the entire coastline of The Netherlands up to 10 km out. The Netherlands is a major shipping hub and the installation of the offshore wind turbines along the entire coastline would not be possible. The realistic length of shoreline and energy available is calculated below. The wind speed map of The Netherlands is shown and will be used as a reference in reasoning about placement of turbines.

www.lowtechmagazine.com/2008/09/urban-windmills.html

Inspection of the map shows the middle section of the coastline has adequate wind speeds and does not have large ports or inlets from the sea. It will be assumed that it would be geographical feasible to place wind turbines along half of the coastline.

Geographically feasible wind power = (104 kWh/d)*(0.5) = 52 kWh/d

The power delivered is (16,500,000)*(52 kWh/d)/(24 hrs/d) = 35.75 GW

Using the 3 MW wind turbines like McKay references, the total number of turbines is calculated as:

(35.75 GW)/(3 MW/turbine)= 11,900 turbines

To erect this many turbines would be an extreme challenge especially as 50 specialized jack up barges would have to be purchased to complete the task in a 10 year period. Each barge has a cost of around 100 million dollars each. Now economic feasibility must be considered. The rough cost of each turbine erected is 3 billion dollars. This would bring the total cost of the project to 41 billion dollars.

The offshore wind power in The Netherlands has increased 1.4 GW in the last 10 years. Even if the rate of the increase doubles over the next ten years, the increase will be 2.8 GW which is well short of the desired 36 GW.

Realistic wind power = current capacity plus increase = 3.8 GW + 2.8 GW = 6.6GW

Realistic wind power per person per day = (6.6GW)*(24 hours)/16500000 = 9.6 kWh/person per day

Wave and Tide

The realistic estimate for wave and tide power will be assessed in the same way. The maximum value was calculated considering 100% of the coastline could be used. As discussed before, this would not work well for The Netherlands as they serve as a major shipping hub.

Realistic wave power = (5.1 kWh/person per day)*(0.5) = 2.55kWh/person per day

Realistic tide power = (12 kWh/d)*(0.5) = 6 kWh/person per day

Biomass

A realistic estimate for the power that could be produced from biomass will be calculated using the estimate in the original green stack analysis. A value of 60% of the total land area was used for the maximum value estimate. This number would be quite high as parts of the land would not be easy to cultivate. The remaining land could not be completely used as 27% of the total area of The Netherlands is used for crop production. A better estimate for the land that could be devoted to biomass production is :

100 - 40 (cities) - 27 (crop) - 20 (not feasible) = 13% of the total area

The maximum value is calculated to be 11.9 kWh/d

The realistic estimate is:

(11.9 kWh/d)*(13/60) = 2.56 kWh/d

Wind and Solar

The estimates for potential wind and solar power were given originally as a realistic numbers and are:

Wind: 22.4 kWh/d

Solar: 11.7 kWh/d

The completed realistic Green stack is compared to the Red Stack below:




The new total for the Green stack is 55 kWh/d. The difference between the stacks is then 70 kWh/d that will need to be supplemented with other sources such as nuclear and fossil fuels. The current energy profile of the country could also be decreased and would lower the red stack resulting in a lower need for additional energy sources.

Land use information obtained from: (1)

Comparing Fuels Sources for Electricity Production

This table gives information on using different types of energy sources for production of electricity. The information has been obtained from the following references:

(17) www.nrel.gov/analysis/power_databook/calc_wind.php
(9) www.eia.gov/oiaf/aeo/electricity_generation.html
(20) thinkgeoenergy.com/archives/2319
(3) www.canadiancleanpowercoalition.com
(22) www.euronuclear.org/info/encyclopedia/u/uranium-reserves.htm
(2) www.reventurepark.com/uploads/1_WTE_ART_18.pdf
(23) www.ftexploring.com/energy/wind-enrgy.html
(6) world-nuclear.org/education/comparativeco2.html




The following pie chart shows the portion of the electrical demand fulfilled by each energy source:

Wave

To calculate the wave energy of the Netherlands a couple of item are needed. The length of coastline, the population and the power in one wave. In Mckay, he uses 40 kW/m as the power of one wave. The Netherlands has a population around 16500000 people and a coastline length of 350km. The power generated can be calculated by the following equation:

(power of one wave)*(coastline length)*(population)

(40 kW/m)*(350,000 m)*(16,500,000 people)*(24 hours/day)=

20.4 kWh per person per day

Now that value is calculated using 100% of the coastline and assuming that the Netherlands is 100% effiecient at turing the wave energy into power which is not possible. Assuming 50% for both the coastline and effieciency is more reasonable but that will decrease the power by 25%.

(20.4)*0.25 = 5.1 kWh per person per day

Biomass

The average havestable sunlight that the Netherlands have is about 100W/m^2. Europes most effiecient plant is close to 0.5% according to Mckay. That brings the value of sunlinght to 0.5 W/m^2. The netherlands is very compact so only 60% of the country could be covered. The enerygh produced by biomass is calculated in the following equations:


(60%)*(41,000 km^2) = 24600 km^2
(24,600 km^2)*(1ooo^2 m^2/km^2)/(16,500,000 people) = 1491 m^2 per person

(0.5 W/m^2)*(1491 m^2/ person)*(24 hours/day) =

17.9 kWh per person per day

This is still not a good assumption because effieciency is still a factor. In Mckay he uses an efficiency of 66.66%.

(2/3)*17.9 = 11.9 kWh per person per day

Green Stack - The Netherlands

Wind

To determine the possibility of powering a portion of The Netherlands on wind energy, the amount of wind power that can be derived from the area must be estimated. To estimate the available wind power, the average wind speed will be referenced. The effective wind speed will then be approximately 1.5 m/s higher than the measured value. To determine the speed of the air at the height of the turbine head, the following formula will be used:

velocity at turbine = (velocity measured)*(height of turbine/height of measurement)^(1/7)

velocity at turbine = (1.5 m/s + 3.8 m/s)*(100 m/10 m)^(1/7) = 7.36 m/s

Using the calculated velocity at the turbine, the power per unit area of the land is calculated as

Power/Area = (pi/400)*density*velocity^3 = (pi/400)*(1.2 )*(7.36)^3 = 3.76 W/m^2

The total area of The Netherlands is 41,000 km^2. Assuming that 10% of the country would be available to wind energy (10% is a high approximation given the dense population of the country) the available power is given as:

Available wind power = (0.10)*(3.76 W/m^2)*(41 x 10^9 m^2) = 15.4 GW

This breaks down per person as

(15.4 x 10^6 kW)*(24 hours)/(16,500,000 people) = 22.4 kWh/(day* person)

Offshore Wind

To determine the amount power that can be generated from offshore wind turbines, the same calculations will be used to determine the available power per unit area as was done for inland wind turbines. The turbine height that will be used is 100 m and the wind measurement height is 15 m.

For the effective wind speed at the turbine:

(1.5 m/s + 7.6 m/s)*(100/15)^(1/7) = 11.9 m/s

To determine the power per unit area of land:

Power/Area = (pi/400)*density*velocity^3 = (pi/400)*(1.2 )*(11.9)^3 = 15.88 W/m^2

Assuming that wind turbines can be installed up to 10 km out from the coastline and that the coastline is 450 km, the total power that could be generated can be determined as:

Power = (15.88 W/m^2)*(450,000 m)*(10,000 m) = 71.5 GW

To convert this into kWh/day per person,

(71.5 x 10^6 kW)*(24 hours/day)/(16,500,000 people) = 104 kWh/day per person

The weight of all the concrete and steel that will be used is determined using a ratio developed from Mckay's method. McKay has stated that 48 kWh per day per person can be produced from 60 million tons of concrete and steel. Setting up a proportion and solving for the unknown weight:

x =(104 kWh)*(60 million tons/48 kWh) = 130 million tons of concrete and steel

That would be the required steel and concrete to create such offshore wind turbines.

Hydro-Electric Power

To determine the potential power that could be developed from hydro-electric generators, the rainfall rate of The Netherlands must be known. The rainfall rate will be specified as the cubic meters of rainfall per second. The average elevation is taken as 322 m. The power can be determined using the potential energy rate created by rainfall.

Rainfall rate = (1.72 x 10^7 cubic meters/year)/(31,536,000 seconds/year) = 0.5454 cubic meters/second

The power can then be calculated by:

Power = (0.5454 cubic meters/sec)*(1000 kg/cubic meter)*(9.81 m/s^2)*(322 m) = 1.72 MW

To convert to kWh per day per person,

(1.72 x 10^3 kW)*(24 hours)/(16,500,000 people) = 0.0025 kWh/day per person

Solar

'The power that could potentially be provided by solar radiation in The Netherlands can be determined using an average of the yearly solar energy per unit area. The average yearly energy value is 1150 kWh/m^2. A factor of 15% will be used as the amount of solar energy that can be converted to electrical energy through the use of solar panels.

(1150 kWh/m^2)*(0.15) = 172.5 kWh/m^2

The area that would need to be covered by solar panels in order to provide all needed power can be calculated as:

(55 kWh/day per person)*(16,500,000 people)*(365 days) = 3.3 x 10^11 kWh

Area required = (3.3 x 10^11)/(172.5 kWh/m^2) = 1.92 x 10^9 sq m = 1.92 x 10^3 sq km

This is nearly 5% of the land area!

That would not be feasible due to the dense population of The Netherlands. To obtain a realistic estimate for the solar power that could be generated, a factor of 1% will be used.

Power = (0.01)*(172.5 kWh/m^2 per year)*(41 x 10^9 m^2)/[(365 days/year)*(16,500,000 people) =

11.74 kWh/day per person


The completed green stack looks like this:

Sources for this post: (14) , (15)

Cost of Production vs Operation

This is a 2000 Chevy Malibu. The average fuel economy has been found to be 30 MPG. The yearly mileage for the vehicle is know to be 30,000 miles. The energy used in the manufacturing is compared to the energy used through the life of the vehicle. The difference between the energies is compared in order to determine how long it will take for the energy in the fuel to equal the energy used in production. The results can be seen here:


The table above is used to generate the following graph:

It can be seen here that the energies will be equal between the third and fourth year. As the life of the car continues, the energy used in production becomes small in comparison to the energy of production. This concept is important in all systems that require energy to operate. It is even more important when creating mechanical systems to generate energy.