Julkaisun nimiInnovators, followers and laggards in home solar PV: Factors driving diffusion in Finland
KirjoittajatEnni Ruokamo, Marita Laukkanen, Santtu Karhinen, Maria Kopsakangas-Savolainen, Rauli Svento
JulkaisijaEnergy Research & Social Science


Generating electricity from solar energy is a way for households to participate in the ongoing transition to decarbonized and more decentralized energy systems. A large empirical literature has examined the drivers and barriers associated with household solar PV adoption. An emerging strand of this literature investigates what distinguishes earlier adopters from later adopters and non-adopters. However, there is yet limited understanding of the differences between earlier and later adopters, as few papers have applied formal statistical models to compare different customer segments. The present study addresses this gap. We examine how the factors that influence household solar PV choices differ between earlier adopters, potential adopters – households that have considered installing solar PV but have not yet done so – and non-adopters. We analyze these choices using rich data from a household-level survey conducted in Finland. The findings show that the adoption of solar PV is linked to a multitude of socio-demographic and financial factors and personal motivations. There are clear differences in the motives and perceptions of adopters, potential adopters, and non-adopters. Accounting for such differences between customer segments will help to better design and target public policy instruments and marketing campaigns that aim to incentivize and nudge households toward solar PV investments.

Julkaisun nimiThe impact of the technical requirements of the renovation grant on the ventilation and indoor air quality in apartment buildings.
KirjoittajatAlo Mikola, Anti Hamburg, Kalle Kuusk, Targo Kalamees, Hendrik Voll, Jarek Kurnitski
JulkaisijaBuilding and environment


In this study, the impact of ventilation requirements set in the conditions of a renovation grant was analysed with field measurements. Effects of renovation measures applied in two grant periods on the air change rate (ACR) and indoor air quality (IAQ) of apartments were examined. CO2 levels and airflow rates were measured in 21 buildings during the first renovation grant period and in 15 buildings in the second grant period. During the first grant period, the average ACR studied apartments was as low as 0.17 h1, and in the second grant period ACR had improved to 0.57 h1, complying with requirements. Room-based ventilation requirements as well as heat recovery and preheating of intake air, mandatory airflow rate and sound pressure level measurement protocols, and third party inspection of design documentation assured adequate ventilation and IAQ in the second grant period. Centralized mechanical supply and exhaust ventilation with heat recovery resulted in best performance but an alternative system with exhaust heat pump and ventilation radiators may also be recommended. We concluded, that the installation of proper ventilation system is a key issue in renovation. The results of the study are a valuable input in designing technical conditions of the renovation grant.

Julkaisun nimiDeterminants of supplementary heating system choices and adoption consideration in Finland
KirjoittajatJouni Räihä, Enni Ruokamo
JulkaisijaEnergy and buildings


Omakotitaloasujat voivat parantaa lämmityksen energiatehokkuutta lisäämällä tukilämmitysjärjestelmän päälämmitysjärjestelmän rinnalle. Päälämmitysjärjestelmävalintaa on tutkittu laajasti, mutta pelkästään tukilämmitysjärjestelmävalintaan keskittyvää tutkimusta on tehty vain vähän. Tämä tutkimus keskittyy tukilämmitysjärjestelmävalintaan ja hankinnan harkintaan. Tutkimus pohjautuu uuden omakotitalon rakentaneille tehtyyn kyselyyn. Hankintapäätösten analysoinnissa käytetään diskreetin valinnan malleja, ja tuloksia tulkitaan innovaatioiden diffuusioteorian kautta. Tutkittavat tukilämmitysjärjestelmät ovat aurinkopaneeli, aurinkokeräin, ilmalämpöpumppu sekä vesitakka. Tulosten mukaan suomalaiset kodinomistajat ovat vastaanottavaisia tukilämmityksen suhteen. Valintapäätökseen vaikuttavia tekijöitä ovat muun muassa ikä, koulutus, ympäristöasenteet sekä informaatiokanavat.


Detached house owners can improve energy efficiency in heating by adding a supplementary heating system alongside the primary mode. Whereas research on primary heating mode adoption is wide, studies focusing solely on the determinants of supplementary heating system adoption is limited. This study examines the determinants of supplementary heating system adoption and consideration in Finland with a survey data collected from a sample of newly built detached house owners. We employ discrete choice modeling to investigate the homeowners’ supplementary heating system choices and interpret the results vis-à-vis the diffusion of innovations literature. The supplementary heating systems under study are solar panel, solar thermal heater, air-source heat pump and water-circulating fireplace. Overall, the findings indicate that homeowners are generally receptive to supplementary heating in Finland. The analyses show that several factors such as age, education, primary heating mode, heating system attributes, location, environmental attitudes and information channels impact the supplementary heating system adoption decision.