October 2019

Program AQUARIUS : Addition of facility to optimise spinning reserve in each load block with amount based on fraction of system demand and/or fixed number of MW, and subject to maximum and minimum that can be provided by each generation plant.


March 2019

Program AQUARIUS : Provision of external Linear Programming 'solver' to rapidly optimise the short term (weekly) operation of complex electricity supply systems with multiple demand areas and hourly load blocks.  


August 2018

Contract signed with the Tanzanian Electricity Supply Company (TANESCO) to supply of an additional copy of Program AQUARIUS for optimising the short-term operation of the national hydro-thermal electricity supply system. Updating of existing AQUARIUS models to represent the 2018 generation and transmission system and optimise hourly outputs and transmission line flows for up to 7 days in advance, based on current reservoir contents, forecast inflows, demand estimates and plant availabilities. Development of 2019 and 2020 models for optimising long-term stored water value operating policies and performing multi-year dynamic simulations. Provision of on-site training. Software maintenance and technical support over 3-year period. 



June 2018

Asian Development Bank TA9003 ‘Integrated Resource Planning with Strategic Environmental Assessment in the Greater Mekong Sub-region (GMS)’. Using the Vietnamese power system as an example, Program CAPRICORN used to demonstrate the practicality of explicitly considering so-called ‘externalities’ when mathematically optimising the expansion of integrated generation and transmission power systems. Imposed constraints included: annual emission targets; annual investment cost limits; Hydrological Condition related hydro plant energy availabilities; the imposition of strategic demand management measures; alternative demands reflecting the introduction of ‘energy efficiency’ measures and associated investment costs. [in association with Ricardo Energy & Environment] 


June 2017

In May 2017, the Asian Development Bank (ADB) agreed a contract variation to the project TA-9003: Integrated Resource Planning (IRP) with Strategic Environmental Assessment (SEA) in the Greater Mekong Sub-region (GMS). The purpose of this variation was to investigate the technical feasibility of considering a range of additional factors (‘externalities’) when mathematically optimising power system expansion plans.

The investigation is to be conducted using the Vietnamese power system as an example, and a contract was signed between Ricardo Energy and Environment and PWSC to undertake the investigation by applying PWSC’s CAPRICORN expansion planning software in combination with the AQUARIUS program used for optimising the operation of integrated water and electricity supply systems.

January 2015:

Program EPSIM : Development of Linear Programming based facility for optimising the expansion of electricity supply systems. Designed to simultaneously optimise the commissioning dates of hydro and other (e.g. thermal, wind, solar and biomass) types of power generation plants, transmission lines, demand areas and interconnections (i.e. imports and exports), while taking account of project interdependencies. Features include demand area specific supply benefits and penalties, minimum energy outputs to reflect PPA conditions, (linear) transmission losses, and compatability with existing EPSIM expansion plan simulation and output routines. Overall development objectives are to facilitate the direct comparison of the costs and benefits associated with adding renwable and non-renewable generation plant with those of strengthening transmission networks and commissioning interconnections.

August 2014:

We are pleased to announce that Andrew (Andy) Pearce has joined PWSC as a senior Consultant. As evidenced by his CV, Andy has acquired considerable experience and expertise in planning the expansion of major electricity systems throughout the world. Most recently, he was Project Manager for the World Bank funded Masterplan Study to optimise expansion of the Ethiopian Generation and Transmission systems over the next 25 years, during which time he gained in depth experience in the application of PWSC's AQUARIUS and EPSIM computer programs.   


July 2014:

Program EPSIM : Facility added to calculate individual project Internal Rates of Return based on their inclusion in given power system expansion plan.


December 2013:

Development of computer programs AQUARIUS and EPSIM to enable account to be taken, within expansion planning processes, of changes in hydro plant capacity and energy availabilities as a function of electricity supply system configuration. Such capabilities can change significantly in the event of capacity increases (phased development),  the commisioning of upstream regulating reservoirs or the introduction of generation plant with significant variations in their seasonal availability. AQUARIUS can now produce Hydro Plant Capability (*.HPC) files for given expansion plan 'years', and these can be directly referenced as part of an EPSIM input data set, allowing such variations to be reflected in load dispatch simulations performed as part of expansion plan evaluations.      

November 2013:

AQUARIUS models constructed to simulate performance of demand/system configuration combinations corresponding to base (WASP IV derived) plan for expanding the Ethiopian electricity generation system. Models constructed for the years 2012, 2016, 2017, 2019, 2020, 2021, 2022, 2023, 2024, 2027, 2032, 2034 and 2037 to include representation of all hydro, thermal and renewable plants planned to be in operation as well as forecast domestic and export electricity demands. Models used to simulate  performance over 45 year historice and reconsituted flow sequence to confirm ability of system to meet demands with acceptable reliability, taking account of significant monthly variations in biomass, wind and solar plant availabilities, and the appropriate scheduling of hydro plant production and balancing of reservoir contents. Outputs included estimates of installed  hydro project capacity and energy capabilities as a function of 'Hydrological Condition' for input to programs WASP and EPSIM.                     

October 2013:

Program EPSIM used to simulate the economic performance of alternative plans for developing the Ethiopian electricity generation system to meet forecast demands up to 2037. Input data files prepared to allow for the commisssioning of 44 hydropower projects, conventional thermal plants (including diesels, single and combined cycle gas turbines), wind farm, geothermal, and biomass projects. Consideration of domestic and 5 existing and potential export markets. Monthly Linear Programming based load dispatch simulation using three load blocks and two Hydrological Conditions to represent 'very dry' and 'average' flow regimes.

March 2013:

AQUARIUS model constructed of the existing system and potential hydro power developments, as part of Ethiopian Power System Master Plan Study.  The model includes 41 reservoirs. 44 hydro plants, 25 flow points, 110 river reaches, 6 river abstractions, 11 water demands, 19 aqueducts, 5 electricity demand centres,and 6 wind plants,

September 2012:

Programs AQUARIUS and EPSIM licensed to PB Power (Parsons Brinkerhoff) and selected for use in forthcoming World Bank funded Ethiopian Power System Master Plan study.

August 2012:

AQUARIUS - Addition of short-term optimisation facility. Least-cost minimisation of system operating costs over user defined horizon of between 1 and 7 days, based on current reservoir contents and forecast inflows, wind speeds, water and electricity demands.

October 2011:

AQUARIUS - Program modified to enable execution under the Windows 7 operating system.

September 2011:

EPSIM - addition of automatic power system expansion plan generation facility. The user can now generate expansion plans covering forecast electricity demands with defined capacity and 'firm' energy reserve percentages in accordance with alternative development strategies, including Cost per MW Installed and Cost per MWh Installed. The generated plans can take into account defined mutual exclusivity and dependency constraints e.g. prior or coincident commissioning of generation plant and transmission line additions.

February 2011: AQUARIUS - Addition of Weibull Distribution option for generating representative daily and hourly wind speeds when modelling wind farms.

November 2010: World Bank funded project 'Provision of Consultancy Services for Hydro/Thermal Dispatch System Upgrade' completed for Tanzania Electric Supply Company Ltd. (TANESCO).

July 2010: Contract signed with Tanzania Electric Supply Company Ltd. (TANESCO) for World Bank funded 'Provision of Consultancy Services for Hydro/Thermal Power Dispatch System Upgrade'.

June 2009: Program AQUARIUS installed in the offices of Tanzania Electric Supply Company Ltd.(TANESCO), together with models for planning long and short term operation of Tanzanian hydro-thermal system. Training given to TANESCO staff in model construction and program applications and usage.

Nov 2008: Contract signed with Tanzania Electric Supply Company Ltd. (TANESCO) for the replacement of Program SYSIM with Program AQUARIUS and Updating of Program SYRAP.

Oct 2008: AQUARIUS - Automated creation of MIMIC diagrams based on system schematics.

Sep 2008: AQUARIUS - Models of existing and potential () Tanzanian hydro-thermal power generation systems completed. 5(10) reservoirs, 21(34) river reaches, 10(16) flow points, 3 river abstractions, 4 supply aqueducts, 6(11) hydro plants, 14 thermal plants, 4 water demand areas and 1 electrcity demand area.

Oct 2007: AQUARIUS - Model of River Dee system (North Wales) completed. 3 reservoirs, 55 river reaches, 26 flow points, 8 river abstractions, 21 supply aqueducts, 6 transfer aqueducts, 3 treatment works, 11 water demands, 3 drought conditions.

Jul 2007: AQUARIUS - Facility added for 'time of travel' through River Reaches, based on up to 7 daily routing coefficients.

Jun 2007: AQUARIUS - Facility added for 7 day 'real time' simulation. Inflow forecasts can be set according to specified 'probability of exceedence' of historic time series values.

Apr 2007: AQUARIUS - Model of integrated Sri Lankan power generation and irrigation supply system completed. 17 reservoirs, 57 river reaches, 30 flow points, 11 river abstractions, 15 supply aqueducts, 13 transfer aqueducts, 13 hydro plants, 7 thermal plants and 15 water (irrigation) demand areas.

Jan 2007: AQUARIUS - Facility added to randomly generate daily flows based on calendar monthly Normal (Gaussian) or Pearson Type III probability distributions. To simulate operation of hydro plant at sites without coincident streamflow records.

Dec 2006: AQUARIUS - Program demonstrated at International Symposium on Water Resources & Renewable Energy Development in Asia, Bangkok 30/11/2006 & 1/12/2006.

Nov 2006: AQUARIUS - Program installed in offices of United Utilities Water, Warrington, UK for evaluation.

Jan 2006: AQUARIUS - Model of United Utility Water's Integrated Water Resource/Supply system constructed. 19 reservoirs, 44 river reaches, 29 flow points, 13 river abstractions, 11 water sources, 19 treatment works, 14 pumping stations, 36 supply aqueducts, 74 transfer aqueducts, 16 junction points and 23 water demand areas.

Oct 2005: AQUARIUS - Modelling of Wind Plants included with random number generation of daily and compatible hourly (load block) wind speeds and defined efficiency function conversion to power output. Enables accurate assessment of wind power values within hydro-thermal power systems.

Aug 2005: AQUARIUS - Optimisation of long-term weekly or monthly stored water values using Stochastic Dynamic Programming Algorithm.