Energy Systems, Markets and Value Chains

Introduction and Context

Energy management is not limited to reducing electricity consumption. It concerns the coordinated design, operation, procurement, and governance of systems that convert primary energy into useful services such as lighting, mobility, industrial production, heating, cooling, and information processing. These systems involve physical infrastructure, commercial contracts, institutions, regulations, technologies, and consumers.

An energy manager therefore needs to understand both engineering and markets. A technically efficient device may be uneconomic if its tariff is poorly matched to its operating pattern. Conversely, a low-cost energy contract may expose an organisation to price volatility, reliability risks, or carbon liabilities. The central task is to align energy services, system performance, financial value, and public objectives.

Energy systems are commonly analysed through four linked dimensions:

1. Physical conversion: extraction, generation, transformation, transmission, distribution, storage, and final use.
2. Economic exchange: prices, tariffs, contracts, auctions, balancing, and investment decisions.
3. Institutional governance: regulation, market rules, ownership, standards, and environmental policy.
4. Security and resilience: adequacy, diversity, reliability, affordability, cybersecurity, and recovery from disruption.

This chapter develops a systems perspective on electricity, fuels, heating, and cooling. It then examines energy value chains, market participants, tariff structures, regulation, and energy-security considerations.

Learning Objectives

By the end of this chapter, the reader should be able to:

• distinguish major energy carriers and energy-system architectures;
• explain the generation-to-use value chain for electricity and fuels;
• compare centralised, decentralised, and integrated energy systems;
• interpret common electricity, gas, fuel, heating, and cooling tariffs;
• identify the principal participants in energy markets and their roles;
• explain why energy markets require regulation and how regulation affects management decisions;
• assess energy security using adequacy, diversity, affordability, resilience, and sustainability criteria;
• calculate basic energy, capacity, efficiency, load-factor, and tariff quantities;
• evaluate practical energy-management choices in an organisational setting.

1. Energy as a System of Services

Energy itself is not usually the final objective. Organisations purchase energy carriers—electricity, natural gas, oil, biomass, district heat, or chilled water—to obtain energy services. Examples include indoor thermal comfort, product drying, refrigeration, transportation, and computing. This distinction matters because the same service can often be delivered by different technologies and carriers.

A useful chain is:

Primary energy → conversion → delivery → end-use technology → energy service

Primary energy exists in natural forms such as sunlight, wind, coal, crude oil, natural gas, uranium, flowing water, and biomass. Conversion technologies transform primary energy into electricity, refined fuels, heat, or hydrogen. Delivery networks then transport the carrier to users. End-use technologies convert it into useful output.

Efficiency must be defined at the boundary being studied. Conversion efficiency is not the same as whole-system efficiency. For a process, the basic efficiency relationship is:

where η is dimensionless efficiency, E_useful is useful energy output, and E_input is energy supplied to the process. The equation applies when input and output are expressed on comparable energy bases and over the same accounting period. If several sequential conversion stages have efficiencies η₁, η₂, …, η_n, the combined efficiency is:

This multiplication assumes that the stages are sequential and that losses at one stage do not alter the stated efficiency of later stages.

Energy is measured in joules in the International System of Units. Electricity billing commonly uses kilowatt-hours (kWh), where:

Power is the rate of energy transfer. One kilowatt is one kilojoule per second. Confusing energy and power is a frequent managerial error: a battery’s capacity is measured in kWh, whereas its maximum charging or discharging rate is measured in kW.

2. Major Energy Systems

2.1 Electricity systems

Electricity systems must maintain a near-continuous balance between generation and demand. Unlike many fuels, electricity cannot generally be stored economically in large quantities without additional storage technologies. System operators therefore coordinate generation, interconnection, demand response, and storage.

A conventional electricity chain includes:

• Generation: production from thermal, hydroelectric, nuclear, wind, solar, geothermal, or other resources;
• Transmission: high-voltage movement over long distances;
• Distribution: lower-voltage delivery to local users;
• Supply and retail: contracting, billing, customer service, and risk management;
• End use: conversion in motors, lighting, electronics, heating, cooling, and industrial equipment.

Voltage is increased by transformers for transmission to reduce current and therefore resistive losses. For a given transmitted power, lower current reduces losses approximately according to:

where P_loss is resistive power loss in watts, I is current in amperes, and R is resistance in ohms. The relationship applies to the relevant conductor segment under the stated operating conditions. It explains why high-voltage transmission is economically important.

Electricity demand varies by time of day, season, weather, production schedule, and consumer behaviour. The load factor measures how fully a system or customer uses its maximum demand:

where E is energy consumed during period T, P_max is maximum demand during that period, and T is the number of hours in the period. Energy must be in kWh and power in kW. Load factor lies between zero and one for a non-negative load. A high load factor generally indicates a smoother demand profile, although it does not by itself prove that equipment is efficient.

2.2 Fuel systems

Liquid and gaseous fuels are energy carriers with important storage advantages. Crude oil is refined into products such as gasoline, diesel, jet fuel, and heating oil. Natural gas may be processed, transported by pipeline, compressed, or liquefied. Coal and biomass can be transported and stored as solid fuels.

Fuel value chains include extraction or cultivation, processing, transport, storage, wholesale trading, retail distribution, and final combustion or conversion. Important management variables include calorific value, moisture, pressure, quality, inventory, transport capacity, and emissions.

Fuel comparisons require a consistent energy basis. A price expressed per tonne, litre, or cubic metre cannot be compared directly with an electricity price per kWh without conversion using the fuel’s energy content and relevant efficiency. The delivered cost of useful energy can be represented as:

where C_useful is cost per unit of useful output, C_carrier is cost per unit of input energy, and η_end_use is end-use efficiency. This is a simplified comparison that excludes capital, maintenance, taxes, network charges, and external costs unless they are added separately.

2.3 Heating systems

Heating may be supplied by direct combustion, electric resistance, heat pumps, combined heat and power, solar thermal systems, biomass systems, or district-heating networks. A heat pump moves heat rather than creating all of it directly. Its performance is commonly described by the coefficient of performance:

where Q̇_heat is useful heating rate in kW thermal and Ẇ_input is electrical or mechanical input rate in kW. COP is not an efficiency in the strict thermodynamic sense and can exceed one because the device transfers ambient or ground heat. COP varies with source temperature, delivery temperature, defrosting, part-load operation, and system design.

District heating can improve efficiency where heat is produced from efficient combined heat and power, waste heat, geothermal resources, or large heat pumps. Its limitations include network losses, high infrastructure costs, customer dependence on a network, and possible lack of supplier choice.

2.4 Cooling systems

Cooling systems remove heat from a conditioned space or process and reject it to the environment. Technologies include vapour-compression chillers, absorption chillers, evaporative cooling, free cooling, district cooling, and thermal-energy storage.

The energy performance ratio for cooling is often expressed as:

where Q̇_cooling is useful cooling rate and Ẇ_input is input power, both commonly expressed in kW. Seasonal indicators aggregate performance across changing outdoor conditions and loads. Comparisons must use the same test conditions and boundary definitions.

Heating and cooling demand is strongly affected by building envelope, internal gains, ventilation, weather, occupancy, control settings, and maintenance. Consequently, replacing equipment without reducing avoidable demand may produce less value than improving insulation, controls, or operating schedules.

Figure: Simplified energy-system value chain

3. Centralised, Decentralised, and Integrated Systems

A centralised system relies on large generators and extensive networks. It can benefit from economies of scale, professional operation, and diversified resources. However, it may involve transmission losses, long permitting processes, concentrated points of failure, and dependence on network infrastructure.

A decentralised system locates generation, storage, or control closer to users. Examples include rooftop solar, batteries, microgrids, local biomass heating, and demand-response systems. Decentralisation can reduce network dependence and enable local resilience, but it may increase coordination complexity and unit costs. Variable renewable generation also creates balancing requirements.

Integrated energy systems coordinate electricity, heating, cooling, transport, and fuels. Electricity may drive heat pumps, electrolysers, or vehicles; thermal storage may reduce electrical peak demand; waste heat may serve a district-heating network. This coupling creates flexibility but also transfers risks between sectors. A power shortage can affect heating, while gas infrastructure constraints can affect electricity generation.

Energy managers should assess systems using whole-life cost, emissions, reliability, flexibility, safety, and exposure to market prices—not merely equipment efficiency.

4. Energy Markets and Their Participants

Energy markets coordinate production, investment, delivery, and consumption. They can be organised through bilateral contracts, competitive wholesale markets, regulated monopolies, auctions, or combinations of these arrangements.

Important participants include:

Market design determines which activities are competitive and which are regulated. Generation and retail may be competitive, while transmission and distribution are often natural monopolies because duplicating networks would be inefficient. Unbundling separates network operation from competitive supply to reduce discriminatory access and conflicts of interest.

Wholesale electricity prices may be formed through bilateral trading, day-ahead markets, intraday markets, balancing markets, and capacity mechanisms. The marginal unit dispatched to meet demand often influences the market-clearing price in energy-only markets. This can produce efficient short-term dispatch but also exposes consumers and generators to volatility.

Retail prices may not move immediately with wholesale prices because suppliers use hedging contracts, regulated tariffs, taxes, and network charges. A consumer’s bill therefore represents several distinct cost categories rather than a single commodity price.

5. Tariff Structures and Energy Costing

A tariff is a structured method for charging for energy-related services. Common components include:

• Energy charge: payment per kWh, litre, therm, or other unit;
• Demand charge: payment based on maximum or contracted power, commonly kW or kVA;
• Fixed charge: recurring payment independent of consumption;
• Time-of-use charge: different prices for peak, shoulder, and off-peak periods;
• Capacity or connection charge: payment for network access or reserved capacity;
• Taxes, levies, and environmental charges;
• Export or feed-in settlement: payment or credit for energy supplied to a network.

A simplified electricity bill is:

where F is the fixed charge, p_t is the energy price in time period t, E_t is consumption in that period, d is the demand-charge rate, P_max is the billed maximum demand, and T represents taxes and other specified charges. The summation covers all tariff periods. Actual tariffs may include ratchets, power-factor penalties, minimum bills, block rates, or contractual exceptions.

Worked example: time-of-use and demand charges

An office uses 12,000 kWh in a month: 5,000 kWh during peak hours at 0.22 currency units/kWh and 7,000 kWh off peak at 0.11 currency units/kWh. Its maximum demand is 80 kW, the demand charge is 9 currency units/kW-month, and the fixed charge is 150 currency units. Ignore tax.

Energy charge:

5,000 × 0.22 = 1,100

7,000 × 0.11 = 770

Demand charge:

80 × 9 = 720

Total bill:

1,100 + 770 + 720 + 150 = 2,740

The average billed cost is 2,740 ÷ 12,000 = 0.2283 currency units/kWh, approximately 0.228 currency units/kWh. This is higher than the simple energy-price average because demand and fixed charges are allocated across consumption.

Tariff analysis should examine both energy efficiency and demand management. A facility may reduce its bill by shifting flexible loads away from peak periods, smoothing start-up sequences, improving power factor where charged, or using storage. However, a measure that reduces peak demand may have little financial value if the tariff has no demand component.

Fuel tariffs often include commodity price, transport, storage, balancing, taxes, and quality adjustments. District-heating and cooling tariffs may combine a fixed connection charge, capacity charge, and metered thermal-energy charge. Managers should verify metering boundaries, temperature differences, pressure conditions, and measurement conventions.

6. Regulation, Governance, and Public Interest

Energy markets have characteristics that justify public regulation. Networks may be natural monopolies; energy supply affects public welfare; pollution creates external costs; and reliability requires coordinated action. Regulation also addresses information asymmetry, market power, safety, consumer protection, and equitable access.

Key regulatory instruments include:

• licensing and technical standards;
• regulated network revenues and access rules;
• wholesale-market monitoring and competition law;
• renewable-energy and efficiency obligations;
• emissions standards, carbon pricing, and environmental permits;
• reliability standards and emergency procedures;
• disclosure, metering, billing, and switching rules;
• building codes and appliance-performance standards;
• public-service obligations and protections for vulnerable consumers.

Regulatory systems involve trade-offs. Strict price controls may protect consumers in the short term but weaken investment signals if prices remain below efficient costs. Market-based pricing can improve allocation but may create affordability problems during price spikes. Renewable support can accelerate innovation while creating subsidy costs or distortions if poorly designed.

Governance must also address procedural fairness. Decisions about transmission lines, wind farms, storage facilities, pipelines, and industrial projects affect land use and communities. Meaningful consultation, transparent evidence, benefit-sharing, and respect for legal rights are essential. Energy managers should not treat compliance as a purely administrative activity: regulatory changes can alter asset values, operating permissions, procurement strategies, and reporting obligations.

7. Energy Security and Resilience

Energy security is the ability of an energy system to provide adequate, reliable, affordable, and sustainable energy despite normal variation and disruption. It is multidimensional rather than equivalent to energy independence.

Important dimensions include:

• Adequacy: sufficient resources and infrastructure to meet expected demand;
• Reliability: acceptable continuity and quality of supply;
• Resilience: ability to withstand, adapt to, and recover from shocks;
• Diversity: avoidance of excessive dependence on one fuel, supplier, route, or technology;
• Affordability: access to energy at manageable cost;
• Sustainability: compatibility with environmental and climate objectives;
• Cyber and physical security: protection against malicious or accidental disruption.

A simple diversity indicator is the Herfindahl–Hirschman Index:

where s_i is the share of supply attributable to source or supplier i, expressed as a fraction between zero and one. A lower HHI indicates greater diversity, while a higher HHI indicates concentration. The indicator is only a screening tool: two sources may appear diverse but share the same pipeline, grid corridor, geopolitical risk, or weather dependence.

Security analysis should consider scenarios rather than only average conditions. Examples include extreme heat, drought, fuel embargo, cyberattack, transmission failure, equipment shortage, sudden price escalation, and prolonged low renewable output. Useful measures include fuel inventories, dual-fuel capability, interconnection, demand response, islandable microgrids, spare equipment, contractual flexibility, emergency generation, and restoration procedures.

Reliability also has an economic dimension. A highly reliable system may require reserve capacity and redundant networks, but excessive redundancy can raise costs. The appropriate standard depends on criticality: a hospital, semiconductor plant, and warehouse may rationally choose different levels of backup.

8. Applied Case: Energy Strategy for a Food-Processing Facility

Background

The following is an illustrative case. A medium-sized food-processing facility operates five days per week, with occasional weekend production. It purchases electricity under a time-of-use tariff and natural gas for steam production. Refrigeration is essential to product quality. The facility experiences high electricity demand during morning start-up and has rising exposure to energy-price volatility.

Problem

The energy manager must reduce operating cost without compromising food safety, production reliability, or legal compliance. A proposed rooftop photovoltaic system would reduce daytime electricity purchases, but management is uncertain whether it should be prioritised over refrigeration controls, boiler maintenance, or peak-demand management.

Analysis

The manager first establishes a baseline using 15-minute electricity data, gas-meter records, production volumes, weather data, and maintenance logs. The analysis identifies four cost drivers:

1. refrigeration operates at unnecessarily low suction pressure during lightly loaded periods;
2. several large motors start simultaneously, creating a high monthly peak;
3. the boiler has poor combustion adjustment and excessive blowdown;
4. solar generation would coincide with much of the daytime load but would not eliminate the morning peak.

The team calculates energy performance per tonne of product rather than relying only on total consumption. This normalises changes in production volume and prevents a misleading conclusion based on reduced output.

Approach and solution

The facility implements a staged programme:

• recommission refrigeration controls and floating head pressure;
• sequence motor starts and reschedule non-critical loads;
• tune the boiler, repair steam leaks, and optimise blowdown;
• install a photovoltaic system sized primarily for on-site use;
• introduce a dashboard showing kWh per tonne, gas per tonne, peak kW, refrigeration COP, and production-adjusted emissions;
• negotiate a contract with partial fixed pricing and defined flexibility provisions.

The sequence is important. Operational measures are implemented before final equipment sizing, avoiding overinvestment based on an inflated baseline. The facility also retains backup generation for critical refrigeration loads and tests emergency procedures.

Outcome

The measures reduce peak demand, improve gas productivity, and increase the proportion of solar electricity consumed on site. The photovoltaic system reduces daytime purchases but does not replace the need for demand management. Management concludes that the best strategy is a portfolio rather than a single technology: efficiency lowers the required capacity, controls reduce tariff exposure, distributed generation reduces purchased electricity, and backup arrangements protect product integrity.

Learning points

• Energy data should be normalised for production and weather.
• The cheapest energy is often energy that need not be purchased.
• Demand charges can justify controls even when total kWh savings are modest.
• On-site generation, storage, and efficiency should be evaluated together.
• Reliability and food safety constraints limit the amount of flexible load.
• Contract design is part of energy management, not a separate procurement issue.

9. Contemporary Developments and Professional Practice

The energy sector is moving toward electrification, renewable generation, storage, digital metering, flexible demand, and sector coupling. Smart meters and automated controls allow prices and operating conditions to influence equipment schedules. Aggregators can combine distributed batteries, electric vehicles, heat pumps, and flexible industrial loads to participate in markets that were previously accessible only to large assets.

Artificial intelligence may support load forecasting, anomaly detection, predictive maintenance, and dispatch optimisation. Its use must remain subordinate to engineering validation and governance. Poor-quality data can produce unreliable recommendations; opaque models can make accountability difficult; and automated control can create safety or cybersecurity risks. Human operators need clear override authority, access controls, audit trails, and tested failure modes.

Best practice in energy management includes:

1. define system boundaries and energy-service objectives;
2. establish a verified baseline and reliable metering plan;
3. separate energy, demand, capacity, and tariff effects;
4. assess whole-life cost and risk rather than simple payback alone;
5. evaluate operational measures before major capital investment;
6. test reliability, safety, cybersecurity, and regulatory compliance;
7. use scenario and sensitivity analysis for prices, weather, and production;
8. monitor outcomes and update assumptions;
9. engage operations, finance, procurement, maintenance, and affected communities;
10. document decisions so that performance claims are auditable.

Major limitations include uncertain future prices, changing regulations, rebound effects, incomplete data, equipment interactions, and the difficulty of assigning benefits among departments. Energy performance contracts and outsourced services can reduce capital barriers, but contract measurement and verification must clearly define baselines, operating conditions, and responsibility for savings.

Chapter Summary

Energy management requires a system-wide understanding of energy carriers, conversion technologies, networks, end-use equipment, markets, and institutions. Electricity systems require continuous balancing and use transmission and distribution networks; fuels offer storage and transport advantages but involve extraction, processing, and supply-chain risks; heating and cooling systems depend strongly on temperature conditions, controls, and useful-output performance.

The generation-to-use value chain creates both costs and risks. Centralised systems benefit from scale, while decentralised and integrated systems can provide flexibility and resilience. Energy markets involve producers, generators, network operators, suppliers, traders, aggregators, regulators, and end users. Tariffs may include energy, demand, fixed, time-of-use, capacity, tax, and export components, so average commodity price is not the same as total delivered cost.

Regulation is necessary because energy networks can be monopolistic, energy is essential, environmental impacts are externalised, and reliability requires coordination. Energy security involves adequacy, reliability, resilience, diversity, affordability, sustainability, and cybersecurity. Effective professional practice combines data, engineering, financial analysis, contract knowledge, stakeholder governance, and scenario planning.

Key Terms

Energy carrier: A medium used to transport or deliver usable energy, such as electricity, natural gas, or hydrogen.

Primary energy: Energy available in natural resources before conversion or processing.

Energy service: The useful outcome obtained from energy, such as comfort, mobility, or production.

Power: The rate of energy transfer, measured in watts or kilowatts.

Load factor: Average demand divided by maximum demand over a specified period.

Generation: Conversion of primary energy into electricity or another useful carrier.

Transmission: High-capacity movement of energy over long distances.

Distribution: Local delivery of energy to final users.

Demand charge: A tariff component based on maximum or contracted power.

Time-of-use tariff: A tariff with prices that vary across defined time periods.

Wholesale market: A market in which energy is traded before retail delivery.

Retail supplier: An organisation that contracts with and bills final customers.

Aggregator: An entity that combines distributed resources for coordinated operation or market participation.

Natural monopoly: A market in which one network can provide service at lower cost than competing duplicate networks.

Coefficient of performance: Useful heating or cooling output divided by input power.

Energy security: The capacity to provide adequate, reliable, affordable, sustainable, and resilient energy.

Resilience: The ability to withstand, adapt to, and recover from disruption.

Energy efficiency: The ratio of useful output or service to energy input, within a defined boundary.

Sector coupling: Coordination and interaction among electricity, heat, cooling, transport, and fuel systems.

Prosumer: A user that both consumes energy and produces, stores, or exports it.

Review Questions

Short Answer Questions

1. Distinguish between energy and power, giving one unit for each.
2. What are the principal stages in an electricity value chain?
3. Why can a heat pump have a coefficient of performance greater than one?
4. Identify four common components of an electricity tariff.
5. Name three dimensions of energy security.

Long Answer Questions

1. Compare centralised and decentralised energy systems, including their economic, technical, and resilience implications.
2. Explain the roles of generators, transmission operators, distribution operators, retailers, system operators, and regulators.
3. Discuss why energy tariffs should be analysed using both energy consumption and maximum demand.
4. Explain how regulation addresses monopoly power, environmental externalities, reliability, and consumer protection.
5. Evaluate the argument that energy independence is sufficient to guarantee energy security.

Analytical / Application Questions

1. A facility consumes 18,000 kWh in a 30-day month and records a maximum demand of 50 kW. Calculate its load factor using 720 hours in the month. Interpret the result.
2. A building can reduce peak demand by 40 kW under a tariff charging 12 currency units per kW-month, or reduce consumption by 4,000 kWh at an energy price of 0.10 currency units/kWh. Compare the monthly bill savings before considering implementation costs.
3. An organisation is choosing between a gas boiler, electric resistance heating, and a heat pump. Design a decision framework that includes useful-energy cost, emissions, reliability, tariff exposure, capital cost, maintenance, and resilience.

Multiple Choice Questions with Answers

Question 1

Which statement best distinguishes power from energy?

A. Power is the rate of energy transfer, while energy is the quantity transferred or consumed.

B. Power is measured only in kWh, while energy is measured only in kW.

C. Power can be stored directly in a fuel tank, while energy cannot.

D. Power and energy are interchangeable terms in tariff analysis.

Correct Answer: A. Power is the rate of energy transfer, while energy is the quantity transferred or consumed.

Question 2

A process receives 100 MJ of energy and delivers 75 MJ of useful output. What is its efficiency?

A. 0.25

B. 0.75

C. 1.33

D. 175%

Correct Answer: B. 0.75

Question 3

Which tariff component is directly based on a customer’s maximum power demand?

A. Fixed charge

B. Energy charge

C. Demand charge

D. Export credit

Correct Answer: C. Demand charge

Question 4

Why are transmission networks operated at high voltage?

A. High voltage eliminates all conversion losses.

B. High voltage allows lower current for a given power, reducing resistive losses.

C. High voltage increases conductor resistance so less energy is delivered.

D. High voltage removes the need for distribution networks.

Correct Answer: B. High voltage allows lower current for a given power, reducing resistive losses.

Question 5

A heat pump supplies 30 kW of heat using 10 kW of electrical input. What is its COP?

A. 0.33

B. 2

C. 3

D. 40

Correct Answer: C. 3

Question 6

Which participant is primarily responsible for maintaining real-time system balance and operational security?

A. Retail customer

B. System operator

C. Fuel producer

D. Appliance manufacturer

Correct Answer: B. System operator

Question 7

What does a lower supplier-concentration HHI generally indicate?

A. Greater diversity of supply

B. Higher maximum demand

C. Lower equipment efficiency

D. Higher network voltage

Correct Answer: A. Greater diversity of supply

Question 8

Which measure most directly reduces a facility’s exposure to an electricity demand charge?

A. Increasing lighting brightness

B. Shifting flexible loads away from the facility’s peak period

C. Purchasing more energy during peak hours

D. Increasing the fixed monthly charge

Correct Answer: B. Shifting flexible loads away from the facility’s peak period

Question 9

Which statement about energy security is most accurate?

A. It is identical to complete domestic energy production.

B. It concerns only the lowest possible energy price.

C. It includes adequacy, reliability, resilience, affordability, diversity, and sustainability.

D. It is achieved whenever a country uses one large energy supplier.

Correct Answer: C. It includes adequacy, reliability, resilience, affordability, diversity, and sustainability.

Question 10

A customer uses 12,000 kWh over 720 hours and has a maximum demand of 50 kW. What is the load factor?

A. 0.167

B. 0.333

C. 0.667

D. 1.200

Correct Answer: C. 0.667