IVCCEIndorama Ventures Center for Clean Energy at Plaksha University

Thermal Energy Storage Techno-Economic Assessment Tool

TES-supported chiller downsizing for a district-cooled residential complex — tank sizing, payback & IRR, levelised cost of storage, and night-time decarbonisation.

1 · Inputs→2 · Downsizing→3 · Results

Inputs

UnitsSIIP
Preview mode. Log in or sign up to change the inputs, run the analysis and upload load profiles.
Cooling load profile
Built-in cities come from the workbook; your uploaded profiles appear here too.
Chiller plant
TR
Chiller downsizing is not an input: the next step sweeps it from 0 to 80 % of this peak.
Constant for the selected load profile — the design chiller before any reduction
Rs/TR
×2 machines: duty + standby
% of chiller capex / yr
Annual maintenance contract, as a percentage of the chiller capex
TES tank
°C
Cold water drawn from the tank to the load
°C
Warm water returned to the tank from the load
%
Share of the tank volume that delivers useful ΔT (stratification figure of merit; 100 % = ideal)
TR·h/m³
ρ·cp·ΔT/3600 × usable volume ÷ 3.51, with water properties at the mean temperature
Rs/m³
%
Energy recovered from the tank as a percentage of the energy put in
Tariffs & PV
Rs/kWh
Rs/kVA/month
–
kgCO2/kWh_e
On-site PV is capped at the daily generation (installed PV × yield); the rest of the day runs on grid
Rs/kWh
Rs/kWh
kWp
kWh/kWp/day
Day / night definition (hour-ending)
HE
HE 19 = 18:00–19:00
HE
HE 9 = 08:00–09:00
Economics (LCOS)
% / yr
Annual TES operation & maintenance, as a percentage of the tank capex
% / yr
% / yr
years
Tariff shift: displaced night electricity at the grid tariff minus charging electricity at the PV tariff (storage effect only). Full hourly: baseline minus with-TES electricity cost, which also includes the part-load COP gain of the downsized chiller. None reproduces the workbook (demand charge + AMC only).
Chiller part-load curve
PLR → COP (12 points)
PLRCOP
Read by a step lookup (largest PLR ≤ actual), as in the workbook. kW/TR = 3.51/COP.
Full night = 15 h (derived). Fixed constant: 3.51 kWh_th per TR·h.
Log in to run the analysis Next: net capex and TES size for 0–80 % chiller downsizing; pick one to open the Technical, Economic and Carbon results.

My load profiles

Registered users can upload their own hourly cooling-load profile (CSV) and size the TES for it. Sign up — it takes a minute.