# -*- coding: utf-8 -*-
## Heat demand provided by a wind turbine, heat pump and water tank
#
# The water tank stores hot water with a standing loss.

import pandas as pd

import pypsa

network = pypsa.Network()

network.set_snapshots(pd.date_range("2016-01-01 00:00", "2016-01-01 03:00", freq="H"))

network.add("Bus", "0", carrier="AC")

network.add("Bus", "0 heat", carrier="heat")

network.add("Carrier", "wind")

network.add("Carrier", "heat")

network.add(
    "Generator",
    "wind turbine",
    bus="0",
    carrier="wind",
    p_nom_extendable=True,
    p_max_pu=[0.0, 0.2, 0.7, 0.4],
    capital_cost=500,
)

network.add("Load", "heat demand", bus="0 heat", p_set=20.0)

# NB: Heat pump has changing efficiency (properly the Coefficient of Performance, COP)
# due to changing ambient temperature
network.add(
    "Link",
    "heat pump",
    bus0="0",
    bus1="0 heat",
    efficiency=[2.5, 3.0, 3.2, 3.0],
    capital_cost=1000,
    p_nom_extendable=True,
)

network.add(
    "Store",
    "water tank",
    bus="0 heat",
    e_cyclic=True,
    e_nom_extendable=True,
    standing_loss=0.01,
)

network.lopf(network.snapshots)

print(pd.DataFrame({attr: network.stores_t[attr]["water tank"] for attr in ["p", "e"]}))

print(pd.DataFrame({attr: network.links_t[attr]["heat pump"] for attr in ["p0", "p1"]}))

print(network.stores.loc["water tank"])

print(network.generators.loc["wind turbine"])