ENERGY MARKETS

Who buys the power, and who keeps the grid steady.

A kilowatt-hour made on a roof in Costa Rica or a clinic in Kenya has to end up as a payment from somebody. This page follows it there: the buyers, the traders, the retailers, the grid operators in between, and the transformer that has to have room for it. Plain language first, the system logic underneath.

Start here

First question: can your site sell power at all?

Here is what this page is about, in one breath. Your roof or your land makes electricity. Some of it you use. The rest has to go somewhere and somebody has to pay for it. Who that is, and whether they are even allowed to, depends entirely on where you are. So the first step in an ANEW project is not choosing panels; it is qualifying the location. Only once we know the route the power can take do we know what a buyer can sign, and therefore what can be financed.

Qualify the location

Is export to the grid permitted for a site your size? Who is allowed to buy it: the utility, a retailer, a contracted off-taker, the market? Is there a queue to connect, and does the local transformer have room?

Pick the route

From the five routes below, the one or two that the location actually supports. Where export is not paid at all, the project is sized for self-consumption and storage.

Contract the buyer

A regulated tariff credit, a retailer's buyback plan, or a power purchase agreement of ten years or more. This contract, not the hardware, is what a basket is written on.

Finance it

The contracted stream, the carbon credits and any incentives are priced, the project joins its country basket, and the note pays for the installation. The ten steps →

Where selling power is possible today, and on what terms

Examples, not an exhaustive list. Rules summarised as understood at the time of writing and they change; a project is qualified against the current rules of its own utility and regulator.

PlaceCan a small site export and get paid?Who buys itPPA or third-party contract?Wholesale route for small sites?
🇨🇷 Costa RicaYes. Distributed generation for self-consumption is permitted and exported power is credited by the distributor at a rate set by the regulator, ARESEP.The local distributor: ICE, CNFL, JASEC, ESPH or one of four rural cooperatives.No household PPA market. Larger private plants sell to ICE under Law 7200, within its caps.No domestic wholesale market. Regional trade on the MER runs through ICE. A single-buyer basket: tariff credits and bill savings, low volatility.
🇺🇸 Texas (ERCOT)Yes where the customer's retail electric provider offers a solar buyback plan. There is no state-mandated net metering in the competitive areas; the buyback is a contract, not a regulation.The retail electric provider the customer chooses. Municipal utilities and cooperatives set their own rules.Yes. Third-party ownership, leases and PPAs are permitted.Yes. ERCOT runs a wholesale market and has been piloting aggregated distributed energy resources, the model for a fleet of small sites trading as one.
🇺🇸 ColoradoYes. Statewide net metering for investor-owned utilities and cooperatives, and community solar gardens since 2010.The utility: Xcel Energy, Black Hills or a cooperative.Yes. Third-party PPAs and leases are common.Not for small sites today; Colorado utilities are moving into regional markets. Net metering plus community solar makes it one of the more open states for small generation.
🇺🇸 CaliforniaYes under the Net Billing Tariff (the 2023 successor to net metering), which credits exports at avoided-cost values and pays far more for power shifted into the evening by storage.The utility (PG&E, SCE, SDG&E) or a community choice aggregator.Yes. PPAs and leases are routine.Yes. CAISO admits distributed energy resource aggregations; interconnection under Rule 21 uses published hosting-capacity maps, the transformer logic on this page made official.
🇰🇪 KenyaSelf-consumption yes; the Energy Act 2019 provides for net metering for systems up to 1 MW, and the 2024 open-access regulations add wheeling.Kenya Power today; eligible consumers and licensed retailers as open access is implemented.Emerging under the 2024 regulations for eligible consumers.Being established under the 2024 regulations. Grid capacity and reliability, not the tariff, drive the design; displaced diesel drives the carbon value.

Why this decides the financing

A Costa Rica basket is written on regulated tariff credits and bill savings. A Texas or California basket would be written on buyback contracts or PPAs, hedged where merchant. A Kenya basket is written on displaced diesel and, as open access lands, on PPAs. A location that cannot export at all still gets a project, sized for self-consumption and storage, and it enters a basket on bill savings alone. The location sets the route, the route sets the contract, and the contract sets the note. That is the order, every time.

In plain language

Five ways a kilowatt-hour gets paid for.

Electricity is the only product that is sold the instant it is made. So the question is never "where do we store it until someone buys it" but "who has already agreed to take it, at what price, and through whose wires." An ANEW site can use one route or several at once.

Route 1

Use it yourself

The site's own load takes the power first. Every kilowatt-hour used on site is a kilowatt-hour not bought from the utility, at the full retail rate, which is usually the most valuable use of all.

System term: self-consumption, behind the meter. No counterparty; the "buyer" is the bill you didn't pay.

Route 2

Sell it to one buyer under a long contract

A company, a utility or a retailer agrees to buy the output for ten years or more at an agreed price. This is a power purchase agreement, and the buyer is called the off-taker.

System term: PPA. Physical if the power is delivered to the buyer's connection; virtual or financial if the buyer settles the price difference against the market and the power goes into the grid.

Route 3

Sell it into the wholesale market

Where a wholesale market exists, power is sold in hourly or quarter-hourly blocks a day ahead, or in the intraday market as the forecast firms up. Small sites cannot trade there directly; a licensed trader or aggregator bundles thousands of them into one tradable position.

System term: day-ahead, intraday and balancing markets, run by an exchange or a system operator. Route-to-market providers such as EDF Trading, Statkraft or Axpo do this for renewable generators.

Route 4

Sell it to a retail electric provider

Retailers buy power wholesale or under PPAs and resell it to homes and businesses on tariffs. A retailer that wants a "100% local renewable" tariff needs generation like this to back it.

System term: retail electric provider, load-serving entity or supplier. Common in the UK, Texas, Australia, the Nordics and much of the EU; absent in single-buyer markets.

Route 5

Sell it to the utility at a regulated rate

In a single-buyer market there is no exchange and no choice of retailer. The state or municipal distributor takes exported power and pays, or credits, a rate set by the regulator. This is the route that applies to a home in Costa Rica today.

System term: single buyer, net billing, regulated tariff. Costa Rica (ICE and seven distributors under ARESEP tariffs) and, historically, Kenya (KPLC) are examples.

For the specialist · what changes between routes

Price risk. Route 5 carries regulatory risk (the tariff can be reset) but no market risk. Route 2 fixes the price for the term and moves basis and shape risk to whoever signed the PPA. Routes 3 and 4 leave the generator exposed to hub prices, capture-rate erosion at midday, and negative prices, which is why merchant exposure is hedged on venues such as CME Group, Nodal Exchange, EEX and Nord Pool, and why the ANEW note programme only admits a site once its output is under a PPA of ten years or more.

Who schedules and who is responsible for imbalance. Any power sold into a market must be nominated to the system operator ahead of time. The party that does that, the balance responsible party, pays imbalance charges when actual output differs from the schedule. For a portfolio of small sites that role sits with the aggregator or trader, never with the household, and it is priced into the route-to-market fee (the "power trading spread" in the scale model).

Attributes travel separately. The renewable certificate (REC, guarantee of origin, I-REC) and any carbon credit are separate instruments from the electricity. They can be sold with the power, bundled into the PPA, or sold on their own venues. The comms board's signed meter record is the provenance all three rest on.

The map

Electrons go one way. Contracts and money go the other.

Three things move at once and they do not follow the same path. The power flows through wires owned by the grid companies. The contracts sit between the site's agent and the buyers. The money comes back through the paying agent to whoever financed the equipment. The meter is the one point all three agree on.

PHYSICAL · THE WIRES COMMERCIAL · THE CONTRACTS FINANCIAL · THE MONEY ANEW site solar · wind · water · storage Comms board meters and signs every quarter-hour at the point of export GENERATION + STORAGE + METER Distribution network the local wires and the substation transformer, which must have room for midday export and evening load DISTRIBUTION OPERATOR · e.g. Enedis, CNFL Transmission grid the system operator keeps supply and demand equal every second: frequency, voltage, reserves SYSTEM OPERATOR · e.g. RTE, PJM, ICE-CENCE kWh MWh Aggregator / trader bundles thousands of sites, forecasts, schedules with the grid operator, carries imbalance risk signed meter data and forecasts schedules · curtailment · loading PPA off-taker corporate, utility or retailer · 10+ years, fixed price Wholesale market day-ahead · intraday · balancing · EPEX, Nord Pool, ISOs Retail electric provider resells on tariffs to homes and businesses contracted output contracted output Single-buyer shortcut Costa Rica today: no trader, no exchange. The distributor is the off-taker at a tariff set by the regulator (ARESEP). Buyers pay monthly for metered delivery PPA invoice · market settlement · tariff credit Trustee and paying agent coupon released on the same signed record · owner keeps the rest cash
Electricity, through the wires Contracts, who agreed to buy Money, back to the site and the note Signed meter data, read by everyone

Organisations named in the diagram are examples of the type of party at each point. ANEW has no agreement with any of them unless stated on this site. ANEW supplies the equipment and the signed data; licensed participants trade and settle.

For the specialist · why the meter is the hinge

Every party in the diagram settles on interval meter data: the off-taker's invoice, the exchange's delivered-volume settlement, the system operator's imbalance calculation, the certificate registry's issuance and the trustee's coupon release. Normally each pulls a different feed on a different clock and reconciles afterwards. The ANEW communications board measures at the export point, signs each quarter-hour with a hardware identity and exposes a read-only interface, so one record serves all of them. That is the technical reason a portfolio of very small sites can be financed as one instrument. It is also why the board carries a calibration record against a named metering standard: an uncalibrated meter cannot settle a trade, in the simulator or in life.

Step by step

How one trade actually settles.

The PPA Trade Simulator on our demo site plays this sequence with a real device signature. In the market it runs like this.

Forecast the output

Nameplate at first, then metered history. The trader forecasts each site and the whole portfolio for tomorrow, hour by hour.

Offer and bid

The forward output is offered for a term. An off-taker bids a price against the reference curve; storage-dispatched power earns a firmness premium because it can be called in the evening.

Sign the contract

Buyer, seller and the venue sign the same trade hash. On ANEW hardware the seller's signature comes from the device's clone-resistant identity, so the contract is bound to the meter that will prove delivery.

Schedule with the grid operator

The balance responsible party nominates the expected volume to the system operator by the day-ahead gate closure and adjusts intraday as the forecast firms.

Deliver through the wires

Power flows into the distribution network. If the local transformer is at its limit the operator can curtail export; storage moves the energy to the evening instead.

Meter and sign

Every quarter-hour of export is measured and signed at the source. Gaps and comms-lost periods are flagged, never estimated.

Settle

Delivered × strike price is invoiced to the off-taker. Schedule minus actual is settled with the system operator as imbalance. Certificates issue per megawatt-hour delivered.

Pay the coupon

The paying agent receives the off-taker's payment, releases the month's note coupon against the same signed record, and passes the remainder to the site owner.

The part most explanations skip

Why the substation transformer decides how much can be sold.

Think of the neighbourhood transformer as a pipe with a fixed width. At noon, hundreds of rooftops push power up the pipe at once. At seven in the evening everyone comes home and pulls power down it. The grid operator only lets a new generator connect if the pipe can take both flows without overheating. Batteries that hold the midday power and release it in the evening make both flows smaller, which is how ANEW sites get connected without waiting years for a substation upgrade.

Substation headroom simulator

Illustrative. One feeder, one transformer, a fleet of identical ANEW homes. Move the sliders.

Assumptions: evening peak 2.2 kW per home, midday household load 0.8 kW, panels at 75% of nameplate at noon, 90% round-trip battery efficiency, transformer loaded to 100% of rating in either direction before an upgrade or curtailment is needed. Real connection studies also check voltage rise, fault level and protection.

Midday · power flowing up the transformer
Evening · power flowing down the transformer
Evening peak without any ANEW systems
transformer rating · export transformer rating · import zero flow 0h12h24h

Gold: net flow with ANEW systems and storage. Grey: the feeder before them. Above the centre line is export toward the grid, below is import from it. Simulation. Illustrative figures from editable assumptions, not an engineering study.

What the grid operator is protecting

Steady state means frequency and voltage stay inside their limits while supply and demand match. The system operator holds reserves and buys balancing energy to keep them matched every second; the distribution operator keeps each transformer and cable inside its thermal rating and each customer's voltage inside its band.

  • Thermal capacity. A transformer rated 1,000 kVA can carry about that much in either direction. Sustained overload shortens its life; a large overload trips it.
  • Voltage rise. Many small generators exporting at minimum load push the voltage up at the end of a feeder. That, not thermal capacity, is often the first constraint.
  • Reverse power flow. Older substations were protected assuming power only flows down. Export needs protection and tap-changer settings checked.
  • Fault level. Every inverter adds a little to the current that flows in a fault; switchgear has a maximum.

How more sites get connected without waiting

Upgrade the substation. A bigger transformer or a second one. Paid by the network company and recovered through everyone's network charges, or charged to the connecting generator depending on the country's connection-charging rules (shallow versus deep).

  • Store and shift. Hold midday export and release it into the evening peak. The ANEW Power Pack and eCUBE do exactly this, which both frees transformer capacity and earns the firmness premium in the trade.
  • Flexible connection. Connect now, accept curtailment in the few hours a year the transformer is full. The comms board at the transformer node reports loading so the curtailment can be targeted.
  • Sell flexibility. Where distribution operators buy it, a fleet of batteries that turns down export on request is paid for it. This is a service, not energy, and it is a growing revenue line for aggregators.

For the specialist · how this appears in an ANEW interconnection

The ANEW communications board sits at four points including the transformer, and measures both sides of the crossing on one clock. In a connection application that is the data the distribution operator asks for: metered export at the point of common coupling, coincident load, and a dispatch profile for the storage. A fleet of sites on one feeder can therefore be presented as a single controllable resource with a bounded midday export and a bounded evening import, which is the case a hosting-capacity study needs, and it is the basis for a non-firm or flexible connection agreement where firm capacity is exhausted. Grid operators do not endorse or certify this data; they read it through the same interface the trustee and the registry read.

Where the first baskets sit

Costa Rica and Kenya, specifically.

The funding page prices two reference sites, a home in Costa Rica and a clinic in Kenya. They sit in very different markets, which is exactly why we run country baskets rather than one global pool.

🇨🇷 Costa Rica · single buyer

The distributor is the off-taker

The Instituto Costarricense de Electricidad, ICE, generates, transmits and dispatches, and remains the country's single buyer of power. Electricity reaches customers through eight distributors: ICE and CNFL (state), JASEC and ESPH (municipal), and the four rural cooperatives Coopelesca, Coopeguanacaste, Coopesantos and Coopealfaroruiz. The regulator, ARESEP, sets every tariff.

  • A home or business generating for its own use connects under the distributed-generation rules and is credited for exported power by its distributor at the regulated rate. There is no exchange, no retailer choice and no household PPA. Route 1 and Route 5.
  • Larger private generators sell to ICE under Law 7200, which caps private generation at 15% of national capacity for build-own-operate plants plus 15% for build-own-transfer plants.
  • Across the border, Costa Rica trades on the Central American regional market, the MER, over the SIEPAC line, run by the regional operator EOR. Proposals to open a domestic wholesale market have been debated; until enacted, the single-buyer model applies.

A bond backed by Costa Rican sites therefore rests on regulated tariff credits and bill savings, not market prices: low volatility, regulatory reset as the main risk. One name to keep apart: ICE here is the Costa Rican utility, not ICE the Intercontinental Exchange named in the venue tables.

🇰🇪 Kenya · opening up

From one buyer to open access

Kenya Power (KPLC) was for decades the only buyer of power and the only retailer. KenGen and independent producers sell to it under PPAs; KETRACO owns the transmission grid; EPRA regulates. In March 2024 the Energy (Electricity Market, Bulk Supply and Open Access) Regulations came into force, providing for open access to the transmission and distribution networks, wheeling, and eligible consumers choosing a supplier.

  • A clinic or workshop today displaces diesel and grid purchases first (Route 1), with the carbon credit worth far more than in Costa Rica because the displaced fuel is dirty.
  • As open access is implemented, a portfolio of sites can be aggregated and wheeled to an off-taker under a PPA (Route 2), or supplied to a licensed retailer (Route 4). Implementation is staged and licence-dependent.
  • Grid capacity is the binding constraint in much of the network, which is why storage-first design and the ability to island matter more here than the tariff does.

Market rules summarised as understood at the time of writing; they change. Nothing here is legal or regulatory advice.

The players

Companies that do this around the world.

Examples of who sits at each point of the chain, so the roles above have faces. EDF is the one most people have heard of because a single group does almost all of them: it generates, it trades and provides route-to-market for other generators, it supplies retail customers, and its regulated network arm runs the distribution grid. Most countries split those roles across several companies.

Company or bodyBasedWhat it does in the chainWhy it matters to a small-site portfolio
Integrated utilities with trading arms · generate, trade, retail
EDF Group
EDF Trading · EDF Renewables · EDF Energy
France; UK, USGenerator and retailer. EDF Trading is the group's wholesale trading arm, giving market access and route-to-market services to renewable generators and small suppliers. Enedis, the French distribution operator, is a regulated EDF subsidiary; RTE, the transmission operator, is independent by law.The template for "one group, every role". A route-to-market desk like EDF Trading is the kind of counterparty that turns thousands of small sites into one schedulable position.
Engie
Global Energy Management & Sales
FranceGenerator, trader and retailer across Europe and Latin America; large corporate PPA seller.Active in Central American generation; a natural PPA counterparty type for regional baskets.
Enel
Enel Green Power · Enel X
ItalyGenerator, retailer and trader. Enel Green Power is among the most active private traders on Central America's regional market, the MER, and operates plants in Costa Rica.Shows that a regional wholesale route already exists next door to the single-buyer Costa Rican market.
IberdrolaSpainGenerator, network owner and retailer in Spain, the UK (ScottishPower), the US (Avangrid), Mexico and Brazil.Runs distribution networks and buys renewable output; both roles in one group.
RWE
RWE Supply & Trading
GermanyGenerator with one of Europe's largest energy trading floors; route-to-market and PPA structuring for third-party renewables.A hedging and aggregation counterparty for merchant exposure.
Vattenfall · Ørsted · StatkraftSweden · Denmark · NorwayState-owned generators. Statkraft is Europe's largest renewable generator and one of its largest PPA providers to third-party wind and solar plants.Long-term PPA off-takers for exactly the kind of small, distributed output a basket contains.
AxpoSwitzerlandTrader and one of the most active PPA counterparties for renewables across Europe and Iberia.Example of a pure market intermediary: no retail customers needed to buy output.
Shell Energy · BPNetherlands, UKOil majors with power trading desks, retail supply and PPA books; Shell owns Next Kraftwerke, a virtual power plant that aggregates thousands of small units.Virtual power plants are the technical model for scheduling a fleet of ANEW sites as one resource.
NextEra Energy Resources · Constellation · VistraUnited StatesLarge generators and wholesale marketers; Constellation and Vistra also retail to businesses and homes in competitive states.The US version of the integrated generator-trader-retailer.
AESUnited StatesGenerator and distributor with operations in Panama, El Salvador and the Dominican Republic.A regional participant familiar with Central American interconnection.
Origin Energy · AGLAustraliaGenerator-retailers in the National Electricity Market; both buy rooftop and battery output through virtual power plant programmes.Rooftop-solar aggregation at scale is already routine in Australia.
Grid and system operators · keep it steady, approve connections
RTE · EnedisFranceRTE runs about 105,000 km of transmission lines and balances the French system; Enedis runs the distribution grid serving some 36 million customers and processes generator connection requests, including substation reinforcement.The two-layer model, transmission operator plus distribution operator, that most countries follow.
PJM · CAISO · ERCOT · MISOUnited StatesIndependent system operators that run wholesale markets and balance the grid across regions; each publishes hub prices that power futures settle against.The hubs named on the funding page's venue table.
National Energy System Operator (NESO) · TenneT · AEMOUK · Netherlands and Germany · AustraliaSystem operators for Great Britain, the Dutch and much of the German grid, and Australia's National Electricity Market.Each runs the balancing and imbalance settlement an aggregator must face.
ICE (Instituto Costarricense de Electricidad) · CENCECosta RicaNational utility, transmission owner, single buyer and, through CENCE, the national dispatch centre.The off-taker of record for a Costa Rican basket. Not the exchange with the same initials.
EOR · CRIECentral AmericaRegional operator and regulator of the MER, the Central American electricity market, over the SIEPAC interconnection.The regional wholesale route available to Costa Rican generation through ICE.
KETRACO · KPLC · EPRAKenyaTransmission company, distributor and retailer, and regulator respectively; EPRA gazetted the 2024 open-access regulations.The bodies that decide how a Kenyan basket's output can be wheeled and sold.
Market venues · where prices are set and hedges cleared
EPEX SPOT · Nord Pool · EEXParis · Oslo · LeipzigDay-ahead and intraday power exchanges for most of Europe, and Europe's power futures and certificate exchange.Reference prices for European PPAs and the venues traders use to hedge them.
CME Group · Nodal Exchange · ICE FuturesChicago · Virginia · AtlantaCleared power futures by US hub, renewable certificates and carbon products.Where the scale model's "trading spread" is actually paid.
Retail providers and PPA infrastructure
Octopus EnergyUnited KingdomRetailer that buys renewable output, including from small generators, and licenses its Kraken platform to other utilities worldwide.Shows a retailer building tariffs directly on distributed generation.
NRG / Reliant · EDF Energy · Engie retailTexas · UK · EuropeRetail electric providers buying wholesale and under PPA, selling to homes and businesses.Route 4 in practice.
LevelTen Energy · PexaparkUnited States · SwitzerlandA marketplace where developers and off-takers arrange PPAs, and a PPA price-reference and risk service.Where the bilateral PPA behind a basket would be arranged and priced.

Roles summarised from each organisation's public descriptions as understood at the time of writing; corporate structures change. These are examples of market participants, not partners, customers or endorsers of ANEW Energy, and no commercial relationship is implied. Trademarks belong to their owners.

The words

A short glossary.

Off-taker. The party contractually obliged to buy the output. In a PPA it is the buyer; in a single-buyer market it is the utility.
PPA, power purchase agreement. A long-term bilateral contract to buy power at a fixed or indexed price. Physical if delivered to the buyer's connection, virtual or financial if settled against a market price.
Wholesale market. Where generators, traders and retailers buy and sell power in bulk: day-ahead auctions, continuous intraday trading and the operator's balancing market.
Retail electric provider. A licensed supplier that buys wholesale or under PPA and sells to end customers on tariffs. Also called a supplier or load-serving entity.
Aggregator, route-to-market provider, virtual power plant. A licensed participant that bundles many small units into one schedulable, tradable position and carries the imbalance risk.
Balance responsible party. The participant that nominates a schedule to the system operator and pays for the difference between schedule and delivery.
TSO / ISO, transmission or independent system operator. Runs the high-voltage grid and balances supply and demand in real time.
DSO, distribution system operator. Owns and runs the local network, substations and transformers, and approves connections to them.
Steady state. Frequency and voltage inside limits with supply equal to demand. What every operator is paid to maintain.
Hosting capacity, headroom. How much extra generation a feeder or transformer can accept before a thermal, voltage or protection limit is hit.
Curtailment. An instruction to reduce export when the network or the system cannot take it. Firm connections are rarely curtailed; flexible connections accept it in exchange for connecting sooner.
Firm power. Output that can be delivered when called, not just when the sun shines. Storage makes solar firm and earns a premium for it.
Imbalance. The gap between what was scheduled and what was delivered in a settlement period, priced by the system operator.
Settlement period. The metering interval trades are settled on: 15 minutes across most of Europe, 30 minutes in Great Britain, 5 to 60 minutes in US markets.
REC, guarantee of origin, I-REC. A certificate proving one megawatt-hour was renewable. Sold with the power or separately.
Single buyer. A market in which one utility purchases all generation and there is no wholesale exchange. Costa Rica today.
Wheeling. Using someone else's network to move power from a generator to a buyer for a fee.
Net billing. A distributed-generation arrangement where exported power is credited at a regulated rate against the customer's bill.

ANEW Energy is not a lender, broker-dealer, investment adviser, electricity trader or licensed supplier. This page is for information only, describes market structures in general terms, and is not an offer of any security, energy contract or service. Market rules differ by jurisdiction and change over time.