Difference between revisions of "Energy balance"

Revision as of 15:09, 21 February 2013

⇤# : Don't put arguments on the same line as a subheading. Check the subheadings, you have some that are not used in methods. --Jouni 22:46, 12 February 2013 (EET)←# : amended according to the comment --Sam0911 10:36, 17 February 2013 (EET)

• The energy calculation based on two core concepts

      1.Energy production or source
      2.Energy consumption

Question

How to calculate energy balances?

--# : Clear question --Sam0911 10:28, 17 February 2013 (EET)

Purpose

where is the purpose?

Boundaries

no info about bouderies?

Procedure

⇤# : No information about the procedure of the assessment? --Sam0911 10:13, 17 February 2013 (EET)

Management

⇤# No information about the management of the assessment?: --Sam0911 10:13, 17 February 2013 (EET) {{{3}}}

Rationale

Input

Output

Data

Calculations

Rationale

New description

• 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)
• 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
  • Equation,
  • Col,
  • Result,
  • Description? ⇤# : This does not join up in a coherent way. --Jouni 17:09, 21 February 2013 (EET)
• Columns for fraction table
  • Class
  • Item
  • Result (fraction)
  • Indices as needed

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)

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.

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.

--# : it seems the formula is ok,the code also runs --Sam0911 16:33, 10 February 2013 (EET)=== Formula ===

Default run key: qffJP3u5RpFw1GuL

library(OpasnetUtils)
library(xtable)

# These three are city-specific: Matrix_page, Additions, Solutions.

Matrix_page <- "Op_en5469" # This is the page with the matrix content.

Additions <- data.frame( # These are additional contents to the matrix, in addition to Matrix_page.
	Equation = "Fraction CHP renewable",
	Col = "CHP peat",
	ETMResult = Frac_CHP_renew,
	ETMDescription = "Actual number given by user."
)

Solutions <- c(rep(0, 18), # These are the solutions (right sides) of the equations.
	Ind_process_heat,
	Cons_Home_electricity,
	Cons_Ind_electricity,
	Cons_Commerce_electricity,
	Cons_Municip_electricity,
	Cons_Home_heat,
	Cons_Ind_heat,
	Cons_Commerce_heat,
	Cons_Municip_heat
)

dependencies <- data.frame(Name = c(
	"Matrix_page",
	"Additions",
	"Solutions"
), Key = "")

formula <- function(dependencies, intermediates = FALSE, ...) {

	ComputeDependencies(dependencies, ...)

	## Define the energy transformation matrix ETM.

	# Get the data from Opasnet Base.

	ETM <- tidy(op_baseGetData("opasnet_base", Matrix_page), objname = "ETM", direction = "wide")

	# Add user-defined data to it.

	ETM <- rbind(ETM, Additions)

	# Reshape the table to make a matrix, and replace NA with 0.

	ETM <- reshape(ETM, timevar = "Col", idvar = "Equation", v.names = "ETMResult", direction = "wide")
	colnames(ETM) <- gsub("ETMResult.", "", colnames(ETM))

	if(intermediates) {print(xtable(ETM), type = 'html')} # Show the matrix with explanations.

	ETM <- as.matrix(ETM[, !colnames(ETM) %in% c("Equation", "ETMDescription")])

	for(i in 1:ncol(ETM)) {
		ETM[is.na(ETM[, i]), i] <- 0
	}

	# Define the outputs for equations (for most equations, it is a zero sum game).

	out <- solve(ETM, Solutions) # Solve the matrix.
	out <- data.frame(Energy.class = colnames(ETM), Result = out)

	return(out)
}

energy.balance <- new("ovariable",
	name = "energy.balance",
	dependencies = dependencies,
	formula = formula
)

temp <- EvalOutput(energy.balance)
print(xtable(temp@output), type = 'html')

objects.put(energy.balance)

cat("Object energy.balance saved. Write down the key of the model run page for further use.\n")

The model first creates the matrix (and shows it to the user if the user has defined intermediates = TRUE), and then it fills all empty cells with 0 and solves it by using the input values the user has given via the user interface. (The user interface can later be replaced by another model.) All the current input values are final consumptions. The example interface and values are based on the Kuopio data, but they are not stored as a part of the ovariable.

--# : good to have a reference to compare --Sam0911 16:12, 10 February 2013 (EET)==See also==

• 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 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

Related files

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