.. _technologies: Technologies ============ This page describes each technology group modelled in GreenBubble: how it is represented in PyPSA, which parameters control its behaviour, and any modelling assumptions worth knowing. Each group corresponds to one or more entries in ``config/n_config.default.yaml`` and is activated by a flag in ``n_flags``. .. note:: This page documents the current technology set. New technologies follow the pattern described in :ref:`guide-new-technology`. --- Renewable electricity (``n_flags.renewables``) ------------------------------------------------- **Onshore wind** and **solar PV** are modelled as ``Generator`` components with capacity-factor time series retrieved from `Renewables.ninja `_ for the configured site coordinates. Both are extendable by default (greenfield) with costs from the technology-data database. Up to ``max_RE_to_grid`` fraction of total renewable output can be exported to the electricity grid; the remainder must be consumed internally. --- Electrolysis (``n_flags.electrolysis``) ------------------------------------------ Alkaline electrolysis is a ``Link`` (electricity → hydrogen) with: - Ramp limits (up/down) to reflect the electrolyser's response speed - Minimum load to avoid operating at inefficient part-load - Committable mode available for brownfield dispatch runs The electrolyser cost is sourced from the IEA via the technology-data database. Efficiency is fixed (no part-load curve); an improved part-load model is planned. --- Biogas and biomass chain (``n_flags.biogas``) ------------------------------------------------ **Biogas plant** — modelled as a ``Generator`` producing raw biogas (CH₄ equivalent) from digestible biomass inputs (manure, co-substrate). Feedstock cost and availability are set in the ``options.Dig biomass`` block of ``n_config.default.yaml``. **Biogas upgrading** — pressure-swing adsorption (PSA) or equivalent, strips CO₂ from raw biogas to yield pipeline-quality biomethane. Modelled as a ``Link`` (raw biogas → biomethane + CO₂). **Biogas compressor** — compresses raw biogas upstream of methanation; modelled as a ``Link`` with electricity input. **Biogas engine** — combined heat-and-power unit; a multi-output ``Link`` (biogas → electricity + heat) with minimum load and optional committable mode for dispatch-only runs. **Belt dryer** — hot-air dryer for biomass pellet production. Semi-empirical sizing based on moisture content. ``expansion: false`` by default — treated as a fixed brownfield asset. **Dewatering** — screw press for digestate solid/liquid separation. Fixed capacity, no expansion. **Pelletization** — biomass pellets production from dried fibres. --- Methanation routes (``n_flags.methanation``) ---------------------------------------------- Two technology pathways are available. Both convert H₂ + CO₂ (or H₂ + biogas) into synthetic methane: **Catalytic methanation** (``methanation CO2``, ``methanation biogas``) — Sabatier reaction. Strict ramp limits (8 %/h) and minimum load (40 %) reflect the thermal inertia of the catalyst bed. **Biomethanation** (``biomethanation CO2``, ``biomethanation biogas``) — Biological hydrogenotrophic process (trickle-bed reactor). Faster ramp response than catalytic (ramp limit 100 %/h); no minimum load constraint in the default configuration. Both are modelled as ``Link`` components. The feed can be CO₂ (from the CO₂ distribution bus) or raw biogas (from the biogas bus). --- Methanol synthesis (``n_flags.meoh``) ---------------------------------------- CO₂ hydrogenation to methanol (``methanolisation``): CO₂ + H₂ → MeOH + H₂O. Modelled as a multi-input ``Link`` with ramp limits (8 %/h) and minimum load (15 %). Waste heat is recovered to the medium-temperature heat bus. An eSMR + methanol synthesis route is planned but not yet implemented. --- Storage (``n_flags.storage``) -------------------------------- All storage components are activated together by the ``storage`` flag. Individual technologies can be disabled by setting ``expansion: false`` and ``initial capacity: 0`` in ``n_config.default.yaml``. .. list-table:: :widths: 25 15 60 :header-rows: 1 * - Component - Type - Notes * - Battery (Li-ion) - StorageUnit - Includes inverter losses; default 2-hour duration * - H₂ HP storage - Store - High-pressure steel vessel; extendable * - CO₂ HP storage - Store - Pressurised cylinders; extendable * - CO₂ Liq storage - Store - Liquefaction + insulated tank; e_nom and liquefaction capacity optimised separately * - TES concrete - StorageUnit - Concrete thermal store; 10-hour duration; standing losses * - TES district heating - StorageUnit - Hot-water buffer for DH; 50-hour duration --- Heat system (``n_flags.central_heat``) ----------------------------------------- Three heat buses represent temperature levels in the cluster: - **Heat MT** (medium temperature) — process waste heat, biomass boilers, biogas engine CHP output - **Heat DH** (district heating) — optional connection to an external DH network (price and load set in ``options.DH``) - **Heat LT** (low temperature) — low-grade cooling and heat pump source A ``heat pump`` link can upgrade LT to DH heat (extendable, disabled by default). ``El boiler`` and ``NG boiler`` provide backup heat. --- Industrial symbiosis (``n_flags.symbiosis``) ----------------------------------------------- The symbiosis flag adds all internal distribution links between plants: electricity, H₂, CO₂, and heat exchange connections across plant boundaries. Disabling it isolates each plant to its own buses, useful for benchmarking individual plant economics. The ``symbiosis El transformer`` (configured under ``options`` in ``n_config.default.yaml``) controls whether the internal electrical transformer between plants is extendable. --- Grid connection ---------------- A ``Link`` representing the point of common coupling (PCC) with the electricity grid. Capacity is extendable by default. Grid import carries the full Danish tariff stack (TSO, DSO, state levies) defined in ``tariffs_dict``; grid export earns the sell tariff. --- External markets ----------------- Configured under the ``options:`` section of ``n_config.default.yaml``: - **Pellets market** — biomass pellet purchase at a fixed price; optional capacity cap - **Moist biomass market** — co-substrate purchase for biogas plant - **Biochar credits** — revenue credit for biochar sequestration from pyrolysis - **CO₂ Liq credits** — revenue credit for liquefied CO₂ export - **District heating** — heat sale to external DH grid (``options.DH``)