Energy balance
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The energy calculation based on two core concepts
- Energy production or source
- Energy consumption
Question
How to calculate energy balances?
Answer
Press button to run the model. Get a free user account and edit the table below to change the model inputs. You may also copy the model to your own page for your own purposes. For examples, see e.g. Energy balance in Kuopio or Energy balance in Suzhou.
Rationale
Input
- Example table for making matrices from text format equations. CHPcapacity describes which of the piecewise linear equations should be used. Policy is a decision option that alters the outcome. Dummy is only for compatibility but it is not used.
Obs | CHPcapacity | Policy | Equation | Dummy | Description |
---|---|---|---|---|---|
1 | Biofuel | CHP renewable = CHP peat | 1 | Biofuel policy contains half biofuels, half peat | |
2 | BAU | CHP renewable = 89.24 | 1 | ||
3 | CHP peat + CHP renewable + CHP oil = CHP heat + CHP electricity | 1 | |||
4 | CHP peat = 90-98*CHP oil | 1 | |||
5 | CHP electricity = 0.689*CHP heat | 1 | |||
6 | CHP<1000 | H heat = 0.08*CHP heat | 1 | Small heat plants reflect the total heat need | |
7 | CHP>1000 | CHP heat + CHP electricity = 1000 | 1 | But production capacity of CHP may be overwhelmed, decoupling CHP heat and H heat. | |
8 | H biogas + H oil = H heat | 1 | |||
9 | H oil = 18.973*H biogas | 1 | |||
10 | Bought electricity + CHP electricity = Cons electricity | 1 | |||
11 | CHP heat + H heat = Cons heat | 1 | |||
12 | Cons electricity = 900-1100 | 1 | |||
13 | Cons heat = 900-1000 | 1 |
- Example table to describe the details about nonlinear equations.
Obs | critVar | critIndex | rescol | critLocLow | critLocHigh | critValue |
---|---|---|---|---|---|---|
1 | Cons heat | CHPcapacity | Result | CHP<1000 | CHP>1000 | 1080 |
- This table is fetched if there are no nonlinearities. Therefore, there is no need to copy it to the case study page.
Obs | critVar | critIndex | rescol | critLocLow | critLocHigh | critValue |
---|---|---|---|---|---|---|
1 |
- This table is fetched if there are no modelled upstream variables that would affect the equations.
Obs | energybalanceVars | Result |
---|---|---|
1 |
Output
Output is an ovariable with column energy.balanceVar for the solved variables, a result column, and all other indices in the balance object used as input. This method has been used in several cases:
- Energy balance in Kuopio
- Energy balance in Basel
- Energy balance in Stuttgart
- Energy balance in Suzhou
Data
- Energy balances are described as input = output on a coarse level (called classes) where the structure is the same or similar to the OECD energy balance tables. If possible, this is described on the Energy balance method level and it is shared by all cities.
- On more detailed (variable level in the matrix), the fraction of each variable of the total class are described separately. Fractions are city specific and they are described on city level in a separate table.
- Based on the fraction table, detailed equations with variables are created. The format will be fraction * class total = variable.
- The last fraction has zero degrees of freedom when the class total is given. However, it must have a variable and thus a row in the fraction table. The result for that variable is an empty cell (which results in NA).
- Unlike in the previous version, all variables are given either as values or equations, and the user interface is not used for BAU. In contrast, user interface or decision table may be used to derive values for alternative scenarios.
- To make this work, the city-specific fraction data must be defined as ovariable (so that it can be changed with a decision table), and also the energy balance method must be described asa ovariable. How are we going to make the two interplay, as we may want to have several cities?
- Define one city ovariable and evaluate energy balance with that. The ovariable has a generic name. Then, define a new city ovariable with the same name and re-evaluate the energy balance ovariable; this must be done so that the two cities are appended rather than replaced.
- city ovariables are appended first into a large fraction table, and then that is used to create the large energy balance matrix. ←--#: . This is clearly better. --Jouni 17:09, 21 February 2013 (EET) (type: truth; paradigms: science: defence)
- The city-specific ovariable may have Iter and other indices. A separate matrix is created and solved for each unique combination of indices. This makes it possible to have a very flexible approach.
- We should check if the energy balance matrix (see Matti's Excel) has city-specific equations. If possible, energy transformations are described as generic equations on the energy balance method.
- Structure of OECD Energy balance tables (data):
- Fuel (given as observation columns in OECD table)
- Activity (row in OECD table)
- Description
- Structure of the generic process table
- Columns for fraction table
- Class
- Item
- Result (fraction)
- Indices as needed
'Additional thoughts
Energy balance has these parts
- General table that describes balances and conversions from ole fuel to another.
- Items and sums Are defined at generic level.
- Data table that contains amounts from OECD table
- Fraction table thAt describes how detailSs Are derived from sums.
- if there Are additions to sta dard items, they descrided at city level in an addition table. It must have the struxture of the matrix table in long format.
- can nonlinearities ne handled simply by indices separating two linear parts of nonlinear equations?
Old description
⇤--#: . What are other energy sources,i wish it should be specific,how about air transport,does it included in the energy balance calculation? --Sam0911 16:29, 10 February 2013 (EET) (type: truth; paradigms: science: attack)
Use a table where different fuel types are columns and different stocks, energy production processes, or consumption types are rows called Energy accounts (Ene.account for short). See also an example File:Energy supply in Europe.xls. All Ene.accounts and fuel types used are listed on Energy consumption classes.
Coal and peat | Crude oil | Petrochemical products | Electricity | Heat | |
---|---|---|---|---|---|
Production and supply of primary energy | |||||
Production | 129 | ||||
Import | 28 | 63 | |||
Export | |||||
Conversion of primary energy to use | |||||
Transfers | |||||
Electricity plants | |||||
CHP plants | -129 | -28 | 61 | 96 | |
Final energy consumption | |||||
Industry | |||||
Road transport | 54 | ||||
Heating | 10 | 96 | |||
Other energy use | 9 | 51 |
Energy balance can be considered as double-entry bookkeeping. The production and conversion are typically credit (i.e., where the energy comes from), while consumption is debit (i.e., where the energy is used). In a typical case, both credit and debit are marked positive on the energy balance sheet. However, there are activities that convert one fuel to another, so that the energy is moved from one column to another. In this case, credit (the source) is marked negative and debit (the target) is marked positive. This is because the production and conversion rows together should reflect how much energy is actually available for final consumption. In other words, the sum of production and conversion rows should equal the sum of the consumption rows in every column.
Because production + conversion = consumption, also production = consumption - conversion. These equations are used to derive the supply that is needed to fulfil the demand.
Calculations
Stored objects used by Energy balance in Kuopio.
- Model version that was used to run results for ISEE2013.
How to give uncertain parameters?
- In equations, the content is interpreted only inside solveMatrix. Therefore, the typical approach where all unique index combinations are run one at a time does not work.
- There should be an update in parameter interpretation for terms with one entry only. It can no longer be based on as.numeric, if distributions (=text) is allowed.
- If it starts with [a-z.] it is a variable name.
- If it starts with [0-9<\\-] it is a parameter value.
- Instead of params[[i]] and [[vars]] vectors, a data.frame will be created with Result as the params column.
- The data.frame is then interpreted with N = N. If parameters are probabilistic, Iter column will appear.
- When all parameters have been interpreted, check if Iter exists.
- If Iter exists, make a for loop for all values of Iter.
- Create a matrix from the parameters and solve.
- Rbind the result to a data.frame with Iter.
- Return the output.
- Old code with an input table with columns Equation, Col, Result, Description: [1]
See also
- TIME: Electric Cars Will Change the Way You Power Your Home. How the homes of the future will generate and store their own electricity, turning your house into a mini-power plant.
- Energy supply in Europe
- media:Health impacts of energy production.ppt (a lecture that also contains explanation of an energy balance using matrices)
- Energy balance in Kuopio Describes the production and consumption of energy in Kuopio.
- Energy balance in Basel
- Energy balance in Stuttgart Describes the production and consumption of energy in Stuttgart.
- Energy balance in Suzhou Describes the production and consumption of energy in Suzhou.
- A previous method to calculate energy balances. Includes also other pages:
- Energy transformations Describes the inputs and outputs of energy processes. Shows, which other things change when some input or output is changed.
- Market allocation factor
- File:Energy supply in Europe.xls
- Climate change policies in Kuopio Indicates, which items change when a policy changes.
- Energiatase
- Kasvihuonekaasupäästöt/Kuopio
- Päätösanalyysia_ja_riskinhallintaa.ppt
- Urgenche
- http://www.energia.fi/sites/default/files/polttoaine-energian_maarittaminen_taselaskennan_avulla.pdf
- Uusiutuvan energian riskit selvitetään
- Urgenche: Mesap Planet energy model
References