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9 LIVE WITHIN YOUR DAILY 'SOLAR ENERGY BUDGET'

This action focuses on the ultimate goal of living within your solar energy 'budget.'

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WHY?

One billion people in the world still use only the amount of energy which is available to them from the sun each day. While these people are not capturing the sun’s energy through solar panels, they capture it through their crops and to passively heat their homes. As fossil fuel sources are depleted, the entire human population will have to return to a life in which we rely on the sun as an energy source as well as other renewables.

Using only the sunlight-energy which is landing on the earth’s surface each day (as opposed to sunlight-energy resources which were formed over millions of years such as oil and coal) will allow us to live in this energy balance again, creating a way of living that can truly sustain itself. Furthermore, sizing our solar arrays to what our need truly is, instead of just replacing coal with sunlight, will allow a more realistic energy future.

While all of the actions within this section are pieces to the puzzle of learning to live within our sustainable energy resources, this last action is the ‘end goal’, to learn what it means to live with only the energy resources we can capture from the sun each day. While this is a difficult actions for individuals to accomplish at this point due to our current infrastructures and system of energy distribution and sourcing, it is a valuable experiment to test what this lifestyle can be like.

how to do this action:

1 - TRACK YOUR CURRENT ENERGY USE:

The first step to reducing energy and finding out how to live within your solar energy budget is to see how much energy you are currently using in your daily lifestyle:

During the ‘tracking week’ before the project begins, track all electricity uses using a meter such as a Kill-A-Watt meter (http://www.p3international.com/products/special/P4400/P4400-CE.html )which counts up kWh over time. If you cannot purchase a meter, look up average watts/hr using online resources. A good online database from the Department of Energy can be found here: Estimating Energy Consumption.

The chart below is an example of tracking electricity uses during a week:

Calculate form
2 - DETERMINE YOUR DAILY SOLAR ENERGY BUDGET:

This action can be accomplished by either calculating the amount of energy which could be hypothetically captured on the roof of your house to create an ‘energy budget’ to live off of for the duration of the project or actually installing solar on your home to truly be living entirely off of the energy which is harvested from the sun each day. The first step to doing either of these, of course, is figuring out how much solar energy can be collected on your roof. These instructions can provide a rough estimate of the solar energy which could be collected.

There are three main factors to consider when sizing a solar array:

  • 1 - The square footage of your roof area.

  • 2 - Solar panel orientation:

  • (A) Solar panels should be angled at 45 degrees (for a Minnesota latitude) in which case they are maximized to capture the most energy per panel throughout the year. However, with this system there must be room left for shadows which will fall on panels located behind. Solar panels are very touchy when it comes to shade. If only a small part of one panel is shaded, the whole system shuts down, so it is important to factor in room for shadows. This reduces the square footage of the roof available for sun capture by a factor of 2.5 on a flat roof (the square footage of your house divided by 2.5), or a lesser factor on sloped roofs. For every degree of roof slope less than 45 degrees, there will be a 1.33% decrease in productive roof area due to the shadows cast by the panels.

  • (B) Solar panels can be placed flat on the roof. This way, you are able to use the most roof area for solar energy capture, however, the angle is not ideal and the efficiency of the panels is reduced by 20%. In addition, the panels are at risk of being covered with snow.

  • 3 - There are different efficiencies for how well solar panels convert sunlight into electricity. Outputs range from 4 watts/sq ft to 20w/sq ft (and more options are being developed). Generally the more expensive the panel, the greater energy output in watts/sq ft you can achieve.

  • ***For the case of this study, we will assume using 45 degree panels with an efficiency of 10 watts/sq ft. ***

To calculate the amount of solar power you can capture on your own roof you will be using the spreadsheet (E9_BASELINE) and will need the following factors:

  • 1 - ‘TOTAL AREA AVAILABLE FOR INSTALLATION’
  • FOR FLAT ROOFS: Find the square footage of your house.
  • FOR SLOPED ROOFS: Determine the roof area that has south (or near south) orientation.

  • * If you are living in an apartment/condo building with multiple levels, use the square footage of your unit.

  • 2 - ROOF SLOPE
  • FOR FLAT ROOFS THIS WILL BE ‘0’.
  • FOR SLOPED ROOFS: Determine the slope, this website (http://www.roofgenius.com/roofpitch.htm) is a good resource)

  • 3 - PANEL EFFICIENCY - (We will be using a standard efficiency of 10 watts/sq ft)

  • 4 - NUBMER OF RESIDENTS LIVING IN HOUSE
  • If you are undertaking this action individually, enter the number of residents that the total solar array is to be divided by. Or, take this action on as a family/group to see if you can limit your total household energy use to the capacity of the solar array (Enter a ‘1’).

  • * If you are living in an apartment/condo building with multiple levels multiply the number of residents living in your unit by the number of levels in your building.

Two case studies are presented below to help you further understand the different ways to go about calculating your daily solar energy budget:

CASE STUDY 1

In CASE STUDY 1 the participant has a total area available for installtion of 1,790 square feet. This number is divided by 2.5 in the spreadsheet to accomodate the 45-degree panels shadows ending up with an actuall square footage of 716 sq ft. Because the roof is flat, a ‘0’ is entered for this cell. By multiplying this number by the capacity of the solar panels (10 watts/sq ft) we end up with a 2864 W/day or a 2.86 kWh/day system. In this case the participant lives in a 3 bedroom duplex. In order to get their ‘share’ of the solar energy, this number must be divided by 3 ending up with a daily energy budget of 2.387 kWh/day.

Calculate form

In CASE STUDY 2, the participant would like to take on this action with his 4-person family in a single family home. They have a south facing roof area of 800 sq ft. The slope of the roof is about 35 degrees so the effective roof area will be decreased somewhat to account for the shadow area of the panels. This is multiplied by the efficiency of 10 watts/sq ft. The total solar array collection is divided by 1 because the partipant will be taking this action on with his entire household. His familiy has a 6.933 kWh/day solar energy budget.

Calculate form
3 - CREATE A PLAN FOR REDUCING YOUR DAILY ENERGY USE TO FIT WITHIN YOUR SOLAR ENERGY BUDGET

Lastly, revisit your baseline energy tracking to come up with a plan for reducing energy to live within your solar energy budget. The chart below is an example of this analysis:

Calculate form

This ‘end-goal’ action calls for participants to reference many of the other actions within this Energy category to acheive the goal of living with their solar budget. For example:

Allow some of the other action's outlines in this section to serve as a guide as you attempt to reduce your energy use.

what will be measured?

KEY QUESTIONS

QUANTITATIVE QUESTION: What is your daily solar energy budget, and how much energy can be saved by reducing your consumption to this amount?

QUALITATIVE QUESTION: How does the experience of living within your solar energy budget affect your happiness, convenience, health and costs?

BASELINE WEEK TRACKING

QUANTITATIVE
During the baseline tracking week before the project begins, use the corresponding spreadsheet (E9_BASELINE) to track your current electricity use:

  • (1) Begin with listing each appliance/electricity user in each room of your house (including a tally of all light bulbs).

  • (2) Make sure to designate the setting of each appliance. List the item twice if different settings are used often.

  • (3) Meter all items. If using a meter such as a Kill-A-Watt meter, the metric which will be given to you is in kWh/hr. Be sure to convert this number to watts/hr before listing on the chart. If you do not have a meter or cannot meter a certain appliance, use online resources to look up averages for these.

  • (4) List the time on per day.

  • (5) In the following column, list the hours on/day as a number without units.

  • (6) Enter all numbers on the Excel spreadsheet to calculate Total Watts/Day and Total kWh/Day. All electricity bills are listed as total kWh per month, so this is an important metric to understand.

QUALITATIVE


Qualitative Scale

Using the above scale as a visual, rate each of the following criteria using the spreadsheet (E9_BASELINE) as it relates to your current energy use:

  • 1. SATISFACTION/HAPPINESS
    (Overall, how much enjoyment or dissatisfaction do you get out of doing and completing this behavior?)

  • 2. CONVENIENCE
    (How easy/difficult and accessible/inaccessible is this behavior for you to do and complete?)

  • 3. HEALTH
    (How healthy/unhealthy and safe/unsafe does this behavior make you feel?)

  • 4. COST
    (How much does this behavior cost? Use positive numbers for being above average and negative numbers for being below average and zero for being average.)

IMPLEMENTATION PHASE TRACKING

QUANTITATIVE
Use the corresponding spreadsheet (E9_QUANTITATIVE) to:

  • 1 - CALCULATE YOUR SOLAR ENERGY BUDGET
  • 2 - CREATE A PLAN FOR REDUCING ENERGY TO FIT WITHIN YOUR SOLAR ENERGY BUDGET
  • (1) Re-list all energy uses from your baseline tracking, settings, wattage and old hours/day.
  • (2) Determine strategies to reduce or eliminate this use by modifying the ‘New Hours/day’ column. First replace all uses which can be eliminated with a ‘0’. If you are still not within your goal, begin to reduce other uses as necessary.
  • 3 - RECORD ACTUAL ENERGY USE
  • On the ‘TOTAL ELECTRIC USAGE’ chart, enter your most recent electric bill (before project began) as a baseline. Then, simply enter your electric use from each monthly bill you receive throughout the project. (in kWh). Determine the energy saved compared to your baseline.

QUALITATIVE
Part 1 - Ranking


Qualitative Scale

Using the above scale as a visual, rate each of the following criteria each week of the project on the spreadsheet (E9_QUALITATIVE) Your answers should not be rated in comparison to your baseline week, but in general as a reflection of how you are feeling.

  • 1. SATISFACTION/HAPPINESS
    (Overall, how much enjoyment or dissatisfaction do you get out of doing and completing this behavior?)

  • 2. CONVENIENCE
    (How easy/difficult and accessible/inaccessible is this behavior for you to do and complete?)

  • 3. HEALTH
    (How healthy/unhealthy and safe/unsafe does this behavior make you feel?)

  • 4. COST
    (How much does this behavior cost? Use positive numbers for being above average and negative numbers for being below average and zero for being average.)

Part 2 - Blogging
Keep a narrative log of your experiences changing this action in your life. How did you reduce your energy use? What were easy things to change? What were the most difficult things to change?


RESOURCES

ACTION SPREADSHEETS

The spreadsheets referred to above can be found in the Excel file at the following link:

E9_Live Within Your Solar Energy Budget Spreadsheet

If you prefer to enter your responses by hand, printable PDFs of each spreadsheet can be found at the following links (at the end of the project, all data will have to be entered into the Excel spreadsheet):

E9_BASELINE
E9_QUANTITATIVE
E9_QUALITATIVE