Variables and style rules

Bold variables need to be discussed.

variable	description	comment
tz	timezone
latitude	latitude
longitude	longitude
dni	direct normal irradiance
dni_extra	direct normal irradiance at top of atmosphere (extraterrestrial)
dhi	diffuse horizontal irradiance
ghi	global horizontal irradiance
aoi	angle of incidence
aoi_projection	cos(aoi)
airmass	airmass
airmass_relative	relative airmass
airmass_absolute	absolute airmass
zenith	solar zenith angle in degrees
apparent_zenith	refraction-corrected solar zenith angle in degrees
azimuth	solar azimuth angle in degrees East of North
poa_ground_diffuse	in plane ground reflected irradiation
poa_direct	direct/beam irradiation in plane
poa_diffuse	total diffuse irradiation in plane. sum of ground and sky diffuse.
poa_global	global irradiation in plane. sum of diffuse and beam projection.
poa_sky_diffuse	diffuse irradiation in plane from scattered light in the atmosphere (without ground reflected irradiation)
surface_tilt	tilt angle of the surface
surface_azimuth	azimuth angle of the surface
solar_zenith	zenith angle of the sun
solar_azimuth	azimuth angle of the sun
temp_cell	temperature of the cell
temp_module	temperature of the module
temp_air	temperature of the air
temp_dew	dewpoint temperature
relative_humidity	relative humidity
v_mp, i_mp, p_mp	module voltage, current, power at the maximum power point
v_oc	open circuit module voltage
i_sc	short circuit module current
i_x, i_xx	Sandia Array Performance Model IV curve parameters
effective_irradiance	effective irradiance
photocurrent	photocurrent
saturation_current	diode saturation current
resistance_series	series resistance
resistance_shunt	shunt resistance